4-Way 3-Position Directional Valve (TL)

Valve for routing flow at the junction of four lines in a thermal liquid network

Libraries:
Simscape / Fluids / Thermal Liquid / Valves & Orifices / Directional Control Valves

Description

The 4-Way 3-Position Directional Valve (TL) block models a valve with four openings in a thermal liquid network, typically between an actuator, pump, and tank. The valve operation is controlled by a single spool displaced according to the signal at port S. You can set the baseline configuration of your valve by specifying the orifices that are open when the spool is in the neutral position (centered at 0 m) in the Neutral spool position open connections parameter, when the spool moves in the positive direction in the Positive spool position open connections parameter, and when the spool moves in the negative direction in the Negative spool position open connections.

You can set the model for valve opening in the Orifice parameterization parameter as a linear relationship or function of user-provided data, which can be applied to one or all flow paths in the valve.

Example Valve Setup

In this example configuration, Neutral spool position open connections is set to All closed. When the spool is in the neutral position, all orifices are closed to flow:

In this configuration, Negative spool position open connections is set to P-A, B-T. When the signal at port S moves the spool to a negative position, the paths between ports P and A and between ports B and T are open to flow. The paths between ports P and B and ports A and T are closed to flow:

In this configuration, Positive spool position open connections is set to P-B, A-T. When the signal at port S moves the spool to a positive position, the paths between ports P and B and between ports A and T are open to flow and the paths between ports P and A and between ports B and T are closed:

Schematically, this configuration is shown as:

The left-hand side corresponds to the positive position and the right-hand side corresponds to the negative position.

Spool Displacement and Valve Configuration

The spool stroke is the amount of spool travel an orifice takes to fully open from a closed position and is defined for each orifice selected on the Valve Configuration tab. The table below shows how the stroke is calculated in accordance with the valve orifice parameterization and flow path characteristics.

The direction of spool movement signaled at port S depends on the spool stroke and the orifice orientation:

Orifice Definition and Spool Travel Direction

Spool Position when Orifice is Open	Spool Travel, ΔS
Always closed (orifice is not selected in any spool position configuration)	N/A
Always open (orifice is selected in positive, neutral, and negative spool position configurations)	N/A
Negative	S_{orifice_max} + spool stroke – S
Negative and Neutral	S_{orifice_max} + spool stroke – S
Positive	S_{orifice_max} – spool stroke + S
Positive and Neutral	S_{orifice_max} – spool stroke + S
Neutral	\|S_{orifice_max}\| + spool stroke – \|S\|
Positive and Negative	–\|S_{orifice_max}\| + spool stroke – \|S\|

Where S_{orifice_max} is the spool position at the maximum orifice area defined for each orifice. The orifice area saturates at the leakage area when ΔS is negative and saturates at the maximum orifice area when the orifice is fully open. When the orifice is fully open, ΔS is equal to the spool stroke, so ΔS greater than the spool stroke does not further increase the orifice area.

The Consistency check for neutral spool position open connections parameter verifies that

Any orifice listed in Neutral spool position open connections is open when the signal at S is 0.
Any orifice that is not listed in Neutral spool position open connections is closed when the signal at S is 0.

You can optionally choose to receive a warning or error when this check is violated.

The possible configurations of the 4-Way 3-Position Directional Valve (TL) block are shown below.

4-Way 3-Position Directional Valve Configuration

Configuration	Parameter Values
	All four orifices are closed in the neutral position. (default) Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `All closed` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum A-T orifice area < –A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
	All four orifices are open in the neutral position. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `P-A, P-B, A-T, B-T` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area < P-A spool stroke Spool position at maximum P-B orifice area > –P-B spool stroke Spool position at maximum A-T orifice area > –A-T spool stroke Spool position at maximum B-T orifice area < B-T spool stroke
	Orifices A-T and B-T are closed. Orifices P-A and P-B are overlapped. Positive spool position open connections: `P-A` Neutral spool position open connections: `All closed` Negative spool position open connections: `P-B` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke
	Orifices A-T and B-T are open. Orifices P-A and P-B are overlapped. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `A-T, B-T` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum A-T orifice area > –A-T spool stroke Spool position at maximum B-T orifice area < B-T spool stroke
	Orifices P-A and A-T are open in the neutral position. Orifices P-B and B-T are overlapped. Positive spool position open connections: `P-B, A-T` Neutral spool position open connections: `P-A, A-T` Negative spool position open connections: `P-A, B-T` Spool position at maximum P-A orifice area < P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area > A-T spool stroke Spool position at maximum B-T orifice area < –B-T spool stroke
	Orifice A-T is open in the neutral position. Orifices P-B, A-T, and B-T are overlapped. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `A-T` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum A-T orifice area > –A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
	Orifice B-T is open in the neutral position. Orifices P-A, P-B, and A-T are overlapped. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `B-T` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum A-T orifice area < –A-T spool stroke Spool position at maximum B-T orifice area < B-T spool stroke
	Orifices P-A, P-B are open. Orifices A-T and B-T are overlapped. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `P-A, P-B` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area < P-A spool stroke Spool position at maximum P-B orifice area > –P-B spool stroke Spool position at maximum A-T orifice area < –A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
	Orifice P-A is open in the neutral position. Orifices P-B, A-T, and B-T are overlapped. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `P-A` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area < P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum A-T orifice area < –A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
	Orifice P-B is open in the neutral position. Orifices P-A, A-T, and B-T are overlapped. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `P-B` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area > –P-B spool stroke Spool position at maximum A-T orifice area < –A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
	Orifices P-B and B-T are open in the neutral position. Orifices P-A and A-T are overlapped. Positive spool position open connections: `P-B, A-T` Neutral spool position open connections: `P-B, B-T` Negative spool position open connections: `P-A, B-T` Spool position at maximum P-A orifice area < –P-A spool stroke Spool position at maximum P-B orifice area < P-B spool stroke Spool position at maximum A-T orifice area > A-T spool stroke Spool position at maximum B-T orifice area > –B-T spool stroke
	Orifices P-A, P-B, A-T, and B-T are closed in the neutral position. P-T is open in the neutral position and closes when the spool displaces. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `P-T` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum A-T orifice area < –A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke Spool position at maximum P-T orifice area = any value
	Orifice P-A is a constant orifice. Orifices P-B, A-T, and B-T are open in the neutral position. Positive spool position open connections: `P-A, P-B` Neutral spool position open connections: `P-A, P-B, A-T, B-T` Negative spool position open connections: `P-A, B-T` Spool position at maximum P-A orifice area < P-A spool stroke Spool position at maximum P-B orifice area < P-B spool stroke Spool position at maximum A-T orifice area = any value Spool position at maximum B-T orifice area > –B-T spool stroke
	Orifice P-B is a constant orifice. Orifices P-A, A-T, B-T are open in the neutral position. Positive spool position open connections: `P-B, A-T` Neutral spool position open connections: `P-A, P-B, A-T, B-T` Negative spool position open connections: `P-A, P-B` Spool position at maximum P-A orifice area > –P-A spool stroke Spool position at maximum A-T orifice area < A-T spool stroke Spool position at maximum B-T orifice area = any value
	Orifice P-A is closed in the neutral position. Ports A and T do not form a flow path. Positive spool position open connections: `P-A, P-B` Neutral spool position open connections: `All closed` Negative spool position open connections: `P-A, B-T` \|Spool position at maximum P-A orifice area\| > P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum B-T orifice area < –B-T spool stroke
	Orifice P-B is closed in the neutral position. Ports B and T do not form a flow path. Positive spool position open connections: `P-B, A-T` Neutral spool position open connections: `All closed` Negative spool position open connections: `P-A, P-B` Spool position at maximum P-A orifice area < –P-A spool stroke \|Spool position at maximum P-B orifice area\| > P-B spool stroke Spool position at maximum A-T orifice area > A-T spool stroke
	Orifice P-A is closed in the neutral position. Orifice A-T is open in the neutral position. Positive spool position open connections: `P-A, P-B` Neutral spool position open connections: `A-T, B-T` Negative spool position open connections: `P-A, B-T` \|Spool position at maximum P-A orifice area\| > P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area = any value Spool position at maximum B-T orifice area > –B-T spool stroke
	Orifice P-B is closed in the neutral position. Orifice B-T is open in the neutral position. Positive spool position open connections: `P-B, A-T` Neutral spool position open connections: `A-T, B-T` Negative spool position open connections: `P-A, P-B` Spool position at maximum P-A orifice area < –P-A spool stroke \|Spool position at maximum P-B orifice area\| > P-B spool stroke Spool position at maximum A-T orifice area < A-T spool stroke Spool position at maximum B-T orifice area = any value
	Orifice P-B is closed in the neutral position. Orifice P-T is open in the neutral position. Ports A and T do not form a flow path. Positive spool position open connections: `P-A, P-B` Neutral spool position open connections: `P-T` Negative spool position open connections: `P-B, A-T` Spool position at maximum P-A orifice area > P-A spool stroke \|Spool position at maximum P-B orifice area\| > P-B spool stroke Spool position at maximum B-T orifice area < –B-T spool stroke Spool position at maximum P-T orifice area = any value
	Orifice P-A is closed in the neutral position. Orifice P-T is open in the neutral position. Ports A and T do not form a flow path. Positive spool position open connections: `P-A, B-T` Neutral spool position open connections: `P-T` Negative spool position open connections: `P-A, P-B` \|Spool position at maximum P-A orifice area\| > P-A spool stroke Spool position at maximum P-B orifice area < –P-B spool stroke Spool position at maximum B-T orifice area > B-T spool stroke Spool position at maximum P-T orifice area = any value

Valve Orifice Parameterizations

The Orifice parameterization parameter sets the model for the open area or volumetric flow rate through one or all of the valve orifices. The block applies the same data for all flow paths if Area characteristics is set to Identical for all flow paths; otherwise, individual parameterizations are applied for the Different for all flow paths setting. You can model valve opening in three ways:

Linear - Area vs. spool travel
The opening area is a linear function of the spool position received as a signal at port S:

$A_{o r i f i c e} = \frac{(A_{\max} - A_{l e a k})}{Δ S_{\max}} Δ S + A_{l e a k},$
where:
- ΔS is the spool travel defined in Spool Displacement and Valve Configuration.
  A_orifice saturates at A_leak when ΔS is negative and saturates at A_max when the orifice is fully open. When the orifice is fully open, ΔS is equal to the spool stroke, so ΔS greater than the spool stroke does not further increase the orifice area.
- ΔS_max is the Spool travel between closed and open orifice.
- A_max is the Maximum orifice area.
- A_leak is the Leakage area.
When the valve is in a near-open or near-closed position in the linear parameterization, you can maintain numerical robustness in your simulation by adjusting the Smoothing factor parameter. If the Smoothing factor parameter is nonzero, the block smoothly saturates the opening area between A_leak and A_max. For more information, see Numerical Smoothing.
Tabulated data - Area vs. spool travel
Provide spool travel vectors for your system or for individual flow paths between ports P, A, B, and T. This data will be used to calculate the relationship between the orifice area and spool displacement. Interpolation is used to determine the opening area between given data points. A_leak and A_max are the first and last parameters of the opening area vector, respectively.
Tabulated data - Volumetric flow rate vs. spool travel and pressure drop
Provide spool travel and pressure drop vectors and a dependent, 2-D volumetric flow rate array. Interpolation is used to determine flow rate between given data points. The mass flow rate is the product of the volumetric flow rate and the local density.

Tabulated data - Mass flow rate vs. spool travel and pressure drop
Calculate the mass flow rate directly from the control member position and the pressure drop across the valve. The relationship between the three variables can be nonlinear, the block calculates it from the tabulated data in the Spool travel vector, ds,Pressure drop vector, dp, and Mass flow rate table, mdot(ds,dp) parameters.

Visualize Orifice Openings

To visualize spool offsets and maximum displacement, right-click the block and select Fluids > Plot Valve Characteristics. The plot shows the orifices selected in the Valve Configuration settings. The orifice parameterization sets the axes, which are either:

Orifice area versus spool position
Volumetric flow rate versus spool position, queried at a specific pressure differential
Mass flow rate versus spool position for the reference inflow temperature and reference inflow pressure, queried at a specific pressure differential

When the positive, neutral, and negative settings in the Valve Configuration feature the same orifice, the plot displays the orifice openings as a constant.

To update the data after changing the block parameters, click Reload Data on the figure window.

This image shows an example valve configuration. In the Valve Configuration settings:

Positive spool position open connections is P-A, B-T.
Neutral spool position open connections is P-T.
Negative spool position open connections is P-B, A-T.

In the P-A Orifice settings:

Spool position at maximum P-A orifice area is 2.5e-3 m.

All other spool positions are at the default values.

Plot of area versus spool position for each orifice.

The visualization shows that the P-A orifice is open between the spool position at -2.53e-3 and 2.53e-3 m. Because the P-A orifice is open only when the spool is displaced in the positive direction, setting the Consistency check for neutral spool and position open connections parameter to Warning returns:

Warning: P-A orifice must be closed when the spool is in the neutral position. Adjust Spool position at maximum P-A orifice area, Neutral spool position open connections, or Consistency check for neutral spool position open connections. Right-click on the block and select Fluids > Plot Valve Characteristics to view the area or flow of each connection versus spool position.

To resolve this warning, you can change:

Spool position at maximum P-A orifice area to a value larger than 0.005 m.
Consistency check for neutral spool position open connections to None.
The valve configuration by setting Neutral spool position open connections to P-A.

Composite Structure

This block is a composite component comprising of multiple instances of the Orifice (TL) block. Refer to the Orifice (TL) block for more detail on the valve parameterizations and block calculations.

Leakage Flow

The primary purpose of the leakage flow rate of a closed valve is to ensure that at no time a portion of the thermal liquid network becomes isolated from the remainder of the model. Such isolated portions reduce the numerical robustness of the model and can slow down simulation or cause it to fail. Leakage flow is generally present in real valves but in a model its exact value is less important than its being a small number greater than zero. The leakage flow rate is determined from the Leakage area block parameter.

Faults

To model a fault, in the Faults section, click the Add fault hyperlink next to the fault that you want to model. Use the fault parameters to specify the fault properties. For more information about fault modeling, see Introduction to Simscape Faults.

The Spool position when faulted parameter has four fault options:

Positive — The spool position freezes in the positive position, opening the flow paths specified by the Positive spool position open connections parameter to their maximum value. The flow paths specified by the Negative spool position open connections and Neutral spool position open connections parameters are closed.
Neutral — The spool position freezes in the neutral position, opening all flow paths to their specified values at 0 m.
Negative — The spool position freezes in the negative position, opening the flow paths specified by the Negative spool position open connections parameter to their maximum value. The flow paths specified by the Positive spool position open connections and Neutral spool position open connections parameters are closed.
Maintain last value — The valve freezes at the spool position when the trigger occurs.

Due to numerical smoothing at the extremes of the valve area, in the linear parameterization, the minimum area that he block uses is larger than the Leakage area, and the maximum is smaller than the Maximum orifice area, in proportion to the Smoothing factor value. For more information, see Numerical Smoothing.

After the fault triggers, the valve remains at the faulted area for the rest of the simulation.

Predefined Parameterization

You can populate the block with pre-parameterized manufacturing data, which allows you to model a specific supplier component.

To load a predefined parameterization:

In the block dialog box, next to Selected part, click the "<click to select>" hyperlink next to Selected part in the block dialogue box settings.
The Block Parameterization Manager window opens. Select a part from the menu and click Apply all. You can narrow the choices using the Manufacturer drop down menu.
You can close the Block Parameterization Manager menu. The block now has the parameterization that you specified.
You can compare current parameter settings with a specific supplier component in the Block Parameterization Manager window by selecting a part and viewing the data in the Compare selected part with block section.

Note

Predefined block parameterizations use available data sources to supply parameter values. The block substitutes engineering judgement and simplifying assumptions for missing data. As a result, expect some deviation between simulated and actual physical behavior. To ensure accuracy, validate the simulated behavior against experimental data and refine your component models as necessary.

To learn more, see List of Pre-Parameterized Components.

Examples

4-Way Directional Valve with Mechanical Effects

Compares two 4-way directional valves, one with mechanical components to account for spool mass, valve spring and damper and one without (ideal valve). The input force to both valves is a sine wave. The operation of two valves are compared for different displacement frequencies, valve spring stiffness and damper coefficients.

Open Model

Aircraft Fuel Supply System with Three Tanks

Model an aircraft fuel supply system consisting of three tanks and an engine.

Open Model

Ports

Input

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S — Spool or valve control member, unitless
physical signal

Instantaneous displacement of the valve control member.

Conserving

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P — Flow passage
thermal liquid

Opening through which the flow can enter or exit the valve. This port is typically connected to a fluid supply line.

T — Flow passage
thermal liquid

Opening through which the flow can enter or exit the valve. This port is typically connected to a fluid return line.

A — Flow passage
thermal liquid

Opening through which the flow can enter or exit the valve. This port is typically connected to an actuation line.

B — Flow passage
thermal liquid

Opening through which the flow can enter or exit the valve. This port is typically connected to an actuation line.

Parameters

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Valve Configuration

Positive spool position open connections — Flow paths open when the spool is in a positive position
`P-A, B-T` (default) | `P-A, P-B` | `P-B, A-T` | `P-A` | `P-B` | `P-A, P-B, A-B`

Flow paths open when the spool is in a positive position. This parameter sets the valve configuration and defines the direction of spool movement according to the signal received at port S. To check the parameter settings for consistency with other orifices, set Consistency check for neutral spool position open connections to Warning or Error.

Neutral spool position open connections — Flow paths open when the spool is in the neutral position
`All closed` (default) | `P-A, P-B, A-T, B-T` | `A-T, B-T` | `P-A, A-T` | `P-A, B-T` | `P-A, P-B` | `P-B, A-T` | `P-B, B-T` | `A-T` | `B-T` | `P-A` | `P-B` | `P-T` | `P-A, A-T, P-T` | `P-A, P-B, A-B` | `P-B, B-T, P-T` | `P-A, P-B, A-T, B-T, P-T`

Flow paths open when the spool is in the neutral position. This parameter sets the valve configuration and defines the direction of spool movement according to the signal received at port S. To check the parameter settings for consistency with other orifices, set Consistency check for neutral spool position open connections to Warning or Error.

Negative spool position open connections — Flow paths open when the spool moves in the negative direction
`P-A, B-T` (default) | `P-A, P-B` | `P-B, A-T` | `P-A` | `P-B` | `P-A, P-B, A-B`

Flow paths open when the spool moves in the negative direction. This parameter sets the valve configuration and defines the direction of spool movement according to the signal received at port S. To check the parameter settings for consistency with other orifices, set Consistency check for neutral spool position open connections to Warning or Error.

Consistency check for neutral spool position open connections — Whether to check if the orifice settings are consistent with the specified spool position for maximum orifice opening
`Warning` (default) | `Error` | `None`

Whether to check if the neutral spool position open settings on the Valve Configuration tab are consistent with the specified spool position at the maximum orifice area. For each enabled orifice, the actual offset at the spool neutral position should be commensurate with the specified spool offset for each individual orifice.

Model Parameterization

Area characteristics — Flow equations for orifices
`Identical for all flow paths` (default) | `Different for each flow path`

Applies uniform or individual flow equations for the valve orifice area. Identical for all flow paths uses the same orifice and spool geometries, flow rates, pressure, and area vectors for all valve orifices. When using Different for each flow path, these parameters are specified individually for each orifice. In both cases, all orifices have the same cross-sectional areas, discharge coefficients, and Reynolds numbers in the Linear - Area vs. spool travel and Tabulated data - Area vs. spool travel parameterizations. The same Orifice parameterization is applied to all flow paths.

Orifice parameterization — Method of calculating opening area
`Linear - Area vs. spool travel` (default) | `Tabulated data - Area vs. spool travel` | `Tabulated data - Volumetric flow rate vs. spool travel and pressure drop` | `Tabulated data - Mass flow rate vs. spool travel and pressure drop`

Method of calculating the valve opening area. In the tabulated data parameterizations, you can provide your own valve area and spool travel data for nonlinear valve opening profiles, or you can provide data in terms of volumetric flow rate, spool travel, and pressure drop over the flow path.

Spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Linear - Area vs. spool travel.

Maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of each orifice during the operation of the valve.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Linear - Area vs. spool travel.

Leakage area — Open area when an orifice is fully closed
`1e-9 m^2` (default) | positive scalar

Open area when an orifice is fully closed. Any area smaller than this value is maintained at the specified leakage area. This parameter contributes to numerical stability by maintaining continuity in the flow.

Dependencies

To enable this parameter, set Orifice parameterization to Linear - Area vs. spool travel.

Spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of valve area. The vector elements must correspond one-to-one with the elements in the Orifice area vector parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Tabulated data - Area vs. spool travel.

Orifice area vector — Vector of valve opening areas
`[1e-09, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Vector of opening areas for the tabular parameterization of valve opening area. The vector elements must correspond one-to-one with the elements in the Spool travel vector parameter. The elements are listed in ascending order and must be greater than 0.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Tabulated data - Area vs. spool travel.

Spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parametrization of volumetric flow rate. The spool travel vector forms an independent axis with the Pressure drop vector, dp parameter for the 2-D dependent Volumetric flow rate table, q(ds,dp) or Mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Pressure drop vector, dp — Vector of valve pressure drop values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure drop values for the tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the Spool travel vector, ds parameter for the 2-D dependent Volumetric flow rate table, q(ds,dp) or Mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

Volumetric flow rate table, q(ds,dp) — Array of volumetric flow rates
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; .00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the Spool travel vector, ds parameter.
N is the number of vector elements in the Pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.

Mass flow rate table, mdot(ds,dp) — Mass flow rate
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the Spool travel vector, ds parameter.
N is the number of vector elements in the Pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Constant orifice area — Orifice area for identical flow paths
`1e-4 m^2` (default) | positive scalar

Orifice area when the positive, neutral, and negative spool positions feature the same orifice.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to either:

Linear - Area vs. spool travel.
Tabulated data - Area vs. spool travel

The same orifice must be selected in all three of the Valve Configuration parameters:

Positive spool position open connections
Neutral spool position open connections
Negative spool position open connections

Constant orifice pressure drop vector — Vector of pressure differential values for identical flow paths
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure differential values over the valve when the positive, neutral, and negative spool positions feature the same orifice. The vector elements correspond one-to-one with the elements in the Constant orifice volumetric flow rate vector or Constant orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

The same orifice must be selected in all three of the Valve Configuration parameters:

Positive spool position open connections
Neutral spool position open connections
Negative spool position open connections

Constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for identical flow paths
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Vector of volumetric flow rate values for a constant orifice when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the Constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

The same orifice must be selected in all three of the Valve Configuration parameters:

Positive spool position open connections
Neutral spool position open connections
Negative spool position open connections

Constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Vector of mass flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the Constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set Area characteristics to Identical for all flow paths and Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

The same orifice must be selected in all three of the Valve Configuration parameters:

Positive spool position open connections
Neutral spool position open connections
Negative spool position open connections

Reference inflow temperature — Temperature at which mass flow rate data is specified
`293.15 K` (default) | positive scalar

Temperature at which the tabulated mass flow rate data is specified.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Reference inflow pressure — Pressure at which mass flow rate tabulated data is specified
`0.101325 MPa` (default) | positive scalar

Pressure at which the tabulated mass flow rate data is specified. The block uses this parameter to calculate a third reference parameter, the reference density. The reference that it uses to scale the tabulated pressure drop data for pressures and temperatures deviating from the reference conditions.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Cross-sectional area at ports P, T, A and B — Area at conserving ports
`0.01 m^2` (default) | positive scalar

Maximum cross-sectional areas at the entry and exit ports P, T, A, and B, which are used in the pressure-flow rate equation that determines the mass flow rate through the valve and energy flow rate smoothing.

Discharge coefficient — Discharge coefficient
`0.64` (default) | positive scalar

Correction factor that accounts for discharge losses in theoretical flows.

Dependencies

To enable this parameter, set Orifice parameterization to either:

Linear - Area vs. spool travel
Tabulated data - Area vs. spool travel

Critical Reynolds number — Upper Reynolds number limit for laminar flow
`150` (default) | positive scalar

Upper Reynolds number limit for laminar flow through the orifice.

Dependencies

To enable this parameter, set Orifice parameterization to:

Linear - Area vs. spool travel
Tabulated data - Area vs. spool travel

Smoothing factor — Numerical smoothing factor
`0.01` (default) | positive scalar in the range of [0,1]

Continuous smoothing factor that introduces a layer of gradual change based to the flow response when the valve is in near-open and near-closed positions. To increase the stability of your simulation in these regimes, set this parameter to a nonzero value less than one.

Dependencies

To enable this parameter, set Orifice parametrization to Linear - Area vs. spool travel.

Pressure recovery — Whether to account for pressure increase in area expansions
`off` (default) | `on`

Whether to account for pressure increase when fluid flows from a region of smaller cross-sectional area to a region of larger cross-sectional area.

Dependencies

To enable this parameter, set Orifice parameterization to:

Linear - Area vs. spool travel
Tabulated data - Area vs. spool travel

P-A Orifice

Spool position at maximum P-A orifice area — Spool offset for fully open P-A orifice
`7.5e-3 m` (default) | positive scalar

Spool offset from the neutral position for a fully open P-A orifice. The Consistency check for neutral spool position open connections parameter will notify you if the values set for this spool position are inconsistent or unphysical according to other orifice spool positions.

Dependencies

To enable this parameter, set one of the following parameters:

Positive spool position open connections to:

P-A, B-T
P-A, P-B
P-A
P-A, P-B, A-B

Neutral spool position open connections to:

P-A, P-B, A-T, B-T
P-A, A-T
P-A, B-T
P-A, P-B
P-A
P-A, A-T, P-T
P-A, P-B, A-B
P-A, P-B, A-T, B-T, P-T

Negative spool position open connections to:

P-A, P-B, A-T, B-T
P-A, A-T
P-A, B-T
P-A, P-B
P-A
P-A, P-B, A-B

Note:

This parameter is enabled only when the P-A orifice settings do not appear in all three spool position parameters: Positive spool position open connections, Neutral spool position open connections, and Negative spool position open connections.

P-A spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel. This value provides an upper limit to calculations so that simulations do not return unphysical values.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of the P-A orifice during the operation of the valve.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Vector of opening areas for the tabular parameterization of valve opening area. The vector elements must correspond one-to-one with the elements in the P-A spool travel vector parameter. The elements are listed in ascending order and must be greater than 0.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of volumetric flow rates. The spool travel vector forms an independent axis with the P-A orifice pressure drop vector, dp parameter for the 2-D dependent P-A orifice volumetric flow rate table, q(ds,dp) or P-A orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A orifice pressure drop vector, dp — Vector of pressure drop values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure drop values for the tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the P-A orifice spool travel vector, ds parameter for the 2-D dependent P-A orifice volumetric flow rate table, q(ds,dp) or P-A orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the P-A orifice spool travel vector, ds parameter.
N is the number of vector elements in the P-A orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the P-A orifice spool travel vector, ds parameter.
N is the number of vector elements in the P-A orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

Orifice area when the positive, neutral, and negative spool positions use the same orifice.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to either:
- Linear - Area vs. spool travel
- Tabulated data - Area vs. spool travel
One of the following settings in each parameter:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure differential values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-A constant orifice volumetric flow rate vector or P-A orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A constant orifice volumetric flow rate vector — Vector of volumetric flow rates for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Vector of volumetric flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-A constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-A constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Vector of mass flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-A constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to:
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, A-T, P-T
- P-A, P-B, A-B
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-A, A-T
- P-A, B-T
- P-A, P-B
- P-A
- P-A, P-B, A-B

P-B Orifice

Spool position at maximum P-B orifice area — Spool offset from the neutral position for a fully open P-B orifice
`7.5e-3 m` (default) | positive scalar

Spool offset from the neutral position for a fully open P-B orifice. The Consistency check for neutral spool position open connections parameter will notify you if the values set for this spool position are inconsistent or unphysical according to other orifice spool positions.

Dependencies

To enable this parameter, set one of the following parameters:

Positive spool position open connections to:

P-B, A-T
P-A, P-B
P-B
P-A, P-B, A-B

Neutral spool position open connections to:

P-A, P-B, A-T, B-T
P-B, A-T
P-B, B-T
P-A, P-B
P-B
P-A, P-B, A-B
P-B, B-T, P-T
P-A, P-B, A-T, B-T, P-T

Negative spool position open connections to:

P-A, P-B, A-T, B-T
P-B, A-T
P-B, B-T
P-A, P-B
P-B
P-A, P-B, A-B

Note:

This parameter is enabled only when the P-B orifice settings do not appear in all three spool position parameters: Positive spool position open connections, Neutral spool position open connections, and Negative spool position open connections.

P-B spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel. This value provides an upper limit to calculations so that simulations do not return unphysical values.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of the P-B orifice during the operation of the valve.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of valve area. The vector elements must correspond one-to-one with the elements in the P-B orifice area vector parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Vector of opening areas for the tabular parameterization of valve opening area. The vector elements must correspond one-to-one with the elements in the P-B spool travel vector parameter. The elements are listed in ascending order and must be greater than 0.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of volumetric flow rates. The spool travel vector forms an independent axis with the P-B orifice pressure drop vector, dp parameter for the 2-D dependent P-B orifice volumetric flow rate table, q(ds,dp) or P-B orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-byn vector

Vector of pressure drop values for tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the P-B orifice spool travel vector, ds parameter for the 2-D dependent P-B orifice volumetric flow rate table, q(ds,dp) or P-B orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the P-B orifice spool travel vector, ds parameter.
N is the number of vector elements in the P-B orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the P-B orifice spool travel vector, ds parameter.
N is the number of vector elements in the P-B orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

Orifice area when the positive, neutral, and negative spool positions use the same orifice.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to either:
- Linear - Area vs. spool travel
- Tabulated data - Area vs. spool travel
One of the following settings in each parameter:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure differential values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-B constant orifice volumetric flow rate vector or P-B orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Vector of volumetric flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-B constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

P-B constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Vector of mass flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-B constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to:
- P-B, A-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- P-B, B-T
- P-A, P-B
- P-B
- P-A, P-B, A-B

A-B Orifice

Spool position at maximum A-B orifice area — Spool offset from the neutral position for a fully open A-B orifice
`7.5e-3 m` (default) | positive scalar

Spool offset from the neutral position for a fully open A-B orifice. The Consistency check for neutral spool position open connections parameter will notify you if the values set for this spool position are inconsistent or unphysical according to other orifice spool positions.

Dependencies

To enable this parameter, set one of the following parameters:

Positive spool position open connections to:

P-A, P-B, A-B

Neutral spool position open connections to:

P-A, P-B, A-B

Negative spool position open connections to:

P-A, P-B, A-B

Note:

A-B spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel. This value provides an upper limit to calculations so that simulations do not return unphysical values.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of the A-B orifice during the operation of the valve.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of valve area. The vector elements must correspond one-to-one with the elements in the A-B orifice area vector parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Vector of opening areas for the tabular parameterization of valve opening area. The vector elements must correspond one-to-one with the elements in the A-B spool travel vector parameter. The elements are listed in ascending order and must be greater than 0.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of volumetric flow rates. The spool travel vector forms an independent axis with the A-B orifice pressure drop vector, dp parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure drop values for tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the A-B orifice spool travel vector, ds parameter for the 2-D dependent A-B orifice volumetric flow rate table, q(ds,dp) or A-B orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the A-B orifice spool travel vector, ds parameter.
N is the number of vector elements in the A-B orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the A-B orifice spool travel vector, ds parameter.
N is the number of vector elements in the A-B orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

Orifice area when the positive, neutral, and negative spool positions use the same orifice.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure differential values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the A-B constant orifice volumetric flow rate vector or A-B orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Vector of volumetric flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the A-B constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-B constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Vector of mass flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the A-B constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to:
- P-A, P-B, A-B
Neutral spool position open connections to:
- P-A, P-B, A-B
Negative spool position open connections to:
- P-A, P-B, A-B

A-T Orifice

Spool position at maximum A-T orifice area — Spool offset from the neutral position for a fully open A-T orifice
`7.5e-3 m` (default) | positive scalar

Spool offset from the neutral position for a fully open A-T orifice. The Consistency check for neutral spool position open connections parameter will notify you if the values set for this spool position are inconsistent or unphysical according to other orifice spool positions.

Dependencies

To enable this parameter, set one of the following parameters:

Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

Note:

This parameter is enabled only when the A-T orifice settings do not appear in all three spool position parameters: Positive spool position open connections, Neutral spool position open connections, and Negative spool position open connections.

A-T spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel. This value provides an upper limit to calculations so that simulations do not return unphysical values.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-B, A-T
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of the A-T orifice during the operation of the valve.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-B, A-T
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of valve area. The vector elements must correspond one-to-one with the elements in the A-T orifice area vector parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Vector of opening areas for the tabular parameterization of valve opening area. The vector elements must correspond one-to-one with the elements in the A-T spool travel vector parameter. The elements are listed in ascending order and must be greater than 0.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of volumetric flow rates. The spool travel vector forms an independent axis with the A-T orifice pressure drop vector, dp parameter for the 2-D dependent A-T orifice volumetric flow rate table, q(ds,dp) or A-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure drop values for tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the A-T orifice spool travel vector, ds parameter for the 2-D dependent A-T orifice volumetric flow rate table, q(ds,dp) or A-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the A-T orifice spool travel vector, ds parameter.
N is the number of vector elements in the A-T orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the A-T orifice spool travel vector, ds parameter.
N is the number of vector elements in the A-T orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

Orifice area when the positive, neutral, and negative spool positions use the same orifice.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to either:
- Linear - Area vs. spool travel
- Tabulated data - Area vs. spool travel
One of the following settings in each parameter:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T constant orifice pressure drop vector — Vector or pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure differential values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the A-T constant orifice volumetric flow rate vector or A-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Vector of volumetric flow rate values when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the A-T constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

A-T constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Vector of mass flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the A-T constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following settings in each parameter:
Positive spool position open connections to P-B, A-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- P-B, A-T
- A-T, B-T
- P-A, A-T
- A-T
- P-A, A-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-B, A-T.

B-T Orifice

Spool position at maximum B-T orifice area — Spool offset from the neutral position for a fully open B-T orifice
`7.5e-3 m` (default) | positive scalar

Spool offset from the neutral position for a fully open B-T orifice. The Consistency check for neutral spool position open connections parameter will notify you if the values set for this spool position are inconsistent or unphysical according to other orifice spool positions.

Dependencies

To enable this parameter, set one of the following parameters:

Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

Note:

This parameter is enabled only when the B-T orifice settings do not appear in all three spool position parameters: Positive spool position open connections, Neutral spool position open connections, and Negative spool position open connections.

B-T spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel. This value provides an upper limit to calculations so that simulations do not return unphysical values.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of the B-T orifice during the operation of the valve.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of spool travel distances for the tabular parameterization of valve area. The vector elements must correspond one-to-one with the elements in the B-T orifice area vector parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Vector of opening areas for the tabular parameterization of valve opening area. The vector elements must correspond one-to-one with the elements in the B-T orifice spool travel vector parameter. The elements are listed in ascending order and must be greater than 0.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of control member travel distances for the tabular parameterization of volumetric flow rates. The spool travel vector forms an independent axis with the B-T orifice pressure drop vector, dp parameter for the 2-D dependent B-T orifice volumetric flow rate table, q(ds,dp) or B-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure drop values for tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the B-T orifice spool travel vector, ds parameter for the 2-D dependent B-T orifice volumetric flow rate table, q(ds,dp) or B-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the B-T orifice spool travel vector, ds parameter.
N is the number of vector elements in the B-T orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the B-T orifice spool travel vector, ds parameter.
N is the number of vector elements in the B-T orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the following parameters:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T constant orifice area — Cross-sectional orifice area for constant orifices
`1e-4 m^2` (default) | positive scalar

Orifice area when the positive, neutral, and negative spool positions use the same orifice.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to either:
- Linear - Area vs. spool travel
- Tabulated data - Area vs. spool travel
One of the settings in each parameter:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure differential values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the B-T constant orifice volumetric flow rate vector or B-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the settings in each parameter:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T constant orifice volumetric flow rate vector — Vector of volumetric flow rates for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Vector of volumetric flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the B-T constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
One of the settings in each parameter:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

B-T constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Vector of mass flow rate values over the valve when the positive, neutral, and negative spool positions use the same orifice. The vector elements correspond one-to-one with the elements in the P-B constant orifice pressure drop vector parameter. The values are listed in ascending order. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
One of the settings in each parameter:
Positive spool position open connections to P-A, B-T.
Neutral spool position open connections to:
- P-A, P-B, A-T, B-T
- A-T, B-T
- P-A, B-T
- P-B, B-T
- B-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T
Negative spool position open connections to P-A, B-T.

P-T Orifice

Spool position at maximum P-T orifice area — Spool offset from the neutral position for a fully open P-T orifice
`0 m` (default) | positive scalar

Spool offset from the neutral position for a fully open P-T orifice. The Consistency check for neutral spool position open connections parameter will notify you if the values set for this spool position are inconsistent or unphysical according to other orifice spool positions.

Dependencies

To enable this parameter, set Neutral spool position open connections to:

P-T
P-A, A-T, P-T
P-B, B-T, P-T
P-A, P-B, A-T, B-T, P-T

P-T spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum distance of spool travel. This value provides an upper limit to calculations so that simulations do not return unphysical values.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

P-T maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Largest open area of the P-T orifice during the operation of the valve.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - Area vs. spool travel.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

P-T orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of control member travel distances for the tabular parameterization of valve area. The vector elements must correspond one-to-one with the elements in the P-T orifice area vector parameter. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

P-T orifice spool travel vector, ds — Vector of spool opening distances relative to fully-closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Vector of control member travel distances for the tabular parameterization of volumetric flow rate. The spool travel vector forms an independent axis with the P-T orifice pressure drop vector, dp parameter for the 2-D dependent P-T orifice volumetric flow rate table, q(ds,dp) or P-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and the first element must be 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

P-T orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Vector of pressure drop values for tabular parametrization of volumetric flow rate. The pressure drop vector forms an independent axis with the P-T orifice spool travel vector, ds parameter for the 2-D dependent P-T orifice volumetric flow rate table, q(ds,dp) or P-T orifice mass flow rate table, mdot(ds,dp) parameters. The values are listed in ascending order and must be greater than 0. Linear interpolation is employed between table data points.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

P-T orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rates
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

M-by-N matrix of volumetric flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the P-T orifice spool travel vector, ds parameter.
N is the number of vector elements in the P-T orifice pressure drop vector, dp parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Area vs. spool travel.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

P-T orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

M-by-N matrix of mass flow rates based on independent values of pressure drop and spool travel distance. M and N are the sizes of the correlated vectors:

M is the number of vector elements in the P-T orifice pressure drop vector, dp parameter.
N is the number of vector elements in the P-T orifice spool travel vector, ds parameter.

Dependencies

To enable this parameter, set:

Area characteristics to Different for each flow path.
Orifice parameterization to Tabulated data - Mass flow rate vs. spool travel and pressure drop.
Neutral spool position open connections to:
- P-T
- P-A, A-T, P-T
- P-B, B-T, P-T
- P-A, P-B, A-T, B-T, P-T

Faults

4-Way 3-Position Directional Valve Area fault — Option to model valve area fault
`Add fault`

Option to model a valve area fault in the block. To add a fault, click the Add fault hyperlink. When a fault occurs, the valve area normally set by the opening parameterization is set based on the value specified in the Spool position when faulted parameter.

Spool position when faulted — Faulted valve characteristics
`Positive` (default) | `Neutral` | `Negative` | `Maintain last value`

Faulted valve spool position. You can choose for the valve to seize when the spool is in the positive position, negative position, or at the position when the fault triggers.

Dependencies

To enable this parameter, click the Add fault hyperlink.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2016a

expand all

R2024b: Model faults with the Simscape faults interface

The 4-Way 3-Position Directional Valve (TL) block now supports the Simscape faults interface. To learn more, see Introduction to Simscape Faults.

R2022b: Right-click blocks to view opening characteristic plots

You can view the plot of the area or volumetric flow rate with respect to spool position for each orifice by right-clicking the block and selecting Fluids > Plot Valve Characteristics.

4-Way 3-Position Directional Valve (TL)

Description

Spool Displacement and Valve Configuration

Valve Orifice Parameterizations

Visualize Orifice Openings

Composite Structure

Leakage Flow

Faults

Predefined Parameterization

Examples

4-Way Directional Valve with Mechanical Effects

Aircraft Fuel Supply System with Three Tanks

Ports

Input

S — Spool or valve control member, unitless physical signal

Conserving

P — Flow passage thermal liquid

T — Flow passage thermal liquid

A — Flow passage thermal liquid

B — Flow passage thermal liquid

Parameters

Valve Configuration

Positive spool position open connections — Flow paths open when the spool is in a positive position P-A, B-T (default) | P-A, P-B | P-B, A-T | P-A | P-B | P-A, P-B, A-B

Negative spool position open connections — Flow paths open when the spool moves in the negative direction P-A, B-T (default) | P-A, P-B | P-B, A-T | P-A | P-B | P-A, P-B, A-B

Consistency check for neutral spool position open connections — Whether to check if the orifice settings are consistent with the specified spool position for maximum orifice opening Warning (default) | Error | None

Model Parameterization

Area characteristics — Flow equations for orifices Identical for all flow paths (default) | Different for each flow path

Orifice parameterization — Method of calculating opening area Linear - Area vs. spool travel (default) | Tabulated data - Area vs. spool travel | Tabulated data - Volumetric flow rate vs. spool travel and pressure drop | Tabulated data - Mass flow rate vs. spool travel and pressure drop

Spool travel between closed and open orifice — Maximum spool stroke 0.005 m (default) | positive scalar

Dependencies

Maximum orifice area — Maximum orifice opening area 1e-4 m^2 (default) | positive scalar

Dependencies

Leakage area — Open area when an orifice is fully closed 1e-9 m^2 (default) | positive scalar

Dependencies

Spool travel vector — Vector of spool opening distances relative to fully closed position [0, .00125, .0025, .00375, .005] m (default) | 1-by-n vector

Dependencies

Orifice area vector — Vector of valve opening areas [1e-09, 1e-05, 4e-05, 6e-05, .0001] m^2 (default) | 1-by-n vector

Dependencies

Spool travel vector, ds — Vector of spool opening distances relative to fully closed position [0, .00125, .0025, .00375, .005] m (default) | 1-by-n vector

Dependencies

Pressure drop vector, dp — Vector of valve pressure drop values [-.1, .3, .5, .7] MPa (default) | 1-by-n vector

Dependencies

Volumetric flow rate table, q(ds,dp) — Array of volumetric flow rates [-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; .00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s (default) | M-by-N matrix

Dependencies

Mass flow rate table, mdot(ds,dp) — Mass flow rate [-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s (default) | M-by-N matrix

Dependencies

Constant orifice area — Orifice area for identical flow paths 1e-4 m^2 (default) | positive scalar

Dependencies

Constant orifice pressure drop vector — Vector of pressure differential values for identical flow paths [-.1, .3, .5, .7] MPa (default) | 1-by-n vector

Dependencies

Constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for identical flow paths [-.0009, .0016, .002, .0024] m^3/s (default) | 1-by-n vector

Dependencies

Constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice [-.9, 1.6, 2, 2.4] kg/s (default) | 1-by-n vector

Dependencies

Reference inflow temperature — Temperature at which mass flow rate data is specified 293.15 K (default) | positive scalar

Dependencies

Reference inflow pressure — Pressure at which mass flow rate tabulated data is specified 0.101325 MPa (default) | positive scalar

Dependencies

Cross-sectional area at ports P, T, A and B — Area at conserving ports 0.01 m^2 (default) | positive scalar

Discharge coefficient — Discharge coefficient 0.64 (default) | positive scalar

Dependencies

Critical Reynolds number — Upper Reynolds number limit for laminar flow 150 (default) | positive scalar

Dependencies

Smoothing factor — Numerical smoothing factor 0.01 (default) | positive scalar in the range of [0,1]

Dependencies

Pressure recovery — Whether to account for pressure increase in area expansions off (default) | on

Dependencies

P-A Orifice

Spool position at maximum P-A orifice area — Spool offset for fully open P-A orifice 7.5e-3 m (default) | positive scalar

Dependencies

P-A spool travel between closed and open orifice — Maximum spool stroke 0.005 m (default) | positive scalar

Dependencies

P-A maximum orifice area — Maximum orifice opening area 1e-4 m^2 (default) | positive scalar

Dependencies

P-A orifice area vector — Vector of valve opening areas [1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2 (default) | 1-by-n vector

Dependencies

P-A orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position [0, .00125, .0025, .00375, .005] m (default) | 1-by-n vector

Dependencies

P-A orifice pressure drop vector, dp — Vector of pressure drop values [-.1, .3, .5, .7] MPa (default) | 1-by-n vector

Dependencies

S — Spool or valve control member, unitless
physical signal

P — Flow passage
thermal liquid

T — Flow passage
thermal liquid

A — Flow passage
thermal liquid

B — Flow passage
thermal liquid

Positive spool position open connections — Flow paths open when the spool is in a positive position
`P-A, B-T` (default) | `P-A, P-B` | `P-B, A-T` | `P-A` | `P-B` | `P-A, P-B, A-B`

Negative spool position open connections — Flow paths open when the spool moves in the negative direction
`P-A, B-T` (default) | `P-A, P-B` | `P-B, A-T` | `P-A` | `P-B` | `P-A, P-B, A-B`

Consistency check for neutral spool position open connections — Whether to check if the orifice settings are consistent with the specified spool position for maximum orifice opening
`Warning` (default) | `Error` | `None`

Area characteristics — Flow equations for orifices
`Identical for all flow paths` (default) | `Different for each flow path`

Orifice parameterization — Method of calculating opening area
`Linear - Area vs. spool travel` (default) | `Tabulated data - Area vs. spool travel` | `Tabulated data - Volumetric flow rate vs. spool travel and pressure drop` | `Tabulated data - Mass flow rate vs. spool travel and pressure drop`

Spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

Maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

Leakage area — Open area when an orifice is fully closed
`1e-9 m^2` (default) | positive scalar

Spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Orifice area vector — Vector of valve opening areas
`[1e-09, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

Spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

Pressure drop vector, dp — Vector of valve pressure drop values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Volumetric flow rate table, q(ds,dp) — Array of volumetric flow rates
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; .00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

Mass flow rate table, mdot(ds,dp) — Mass flow rate
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

Constant orifice area — Orifice area for identical flow paths
`1e-4 m^2` (default) | positive scalar

Constant orifice pressure drop vector — Vector of pressure differential values for identical flow paths
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

Constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for identical flow paths
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

Constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Reference inflow temperature — Temperature at which mass flow rate data is specified
`293.15 K` (default) | positive scalar

Reference inflow pressure — Pressure at which mass flow rate tabulated data is specified
`0.101325 MPa` (default) | positive scalar

Cross-sectional area at ports P, T, A and B — Area at conserving ports
`0.01 m^2` (default) | positive scalar

Discharge coefficient — Discharge coefficient
`0.64` (default) | positive scalar

Critical Reynolds number — Upper Reynolds number limit for laminar flow
`150` (default) | positive scalar

Smoothing factor — Numerical smoothing factor
`0.01` (default) | positive scalar in the range of [0,1]

Pressure recovery — Whether to account for pressure increase in area expansions
`off` (default) | `on`

Spool position at maximum P-A orifice area — Spool offset for fully open P-A orifice
`7.5e-3 m` (default) | positive scalar

P-A spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

P-A maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

P-A orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

P-A orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

P-A orifice pressure drop vector, dp — Vector of pressure drop values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

P-A orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

P-A orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

P-A constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

P-A constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

P-A constant orifice volumetric flow rate vector — Vector of volumetric flow rates for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

P-A constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Spool position at maximum P-B orifice area — Spool offset from the neutral position for a fully open P-B orifice
`7.5e-3 m` (default) | positive scalar

P-B spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

P-B maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

P-B orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

P-B orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

P-B orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

P-B orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-byn vector

P-B orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

P-B orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

P-B constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

P-B constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

P-B constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

P-B constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Spool position at maximum A-B orifice area — Spool offset from the neutral position for a fully open A-B orifice
`7.5e-3 m` (default) | positive scalar

A-B spool travel between closed and open orifice — Maximum spool stroke
`0.005 m` (default) | positive scalar

A-B maximum orifice area — Maximum orifice opening area
`1e-4 m^2` (default) | positive scalar

A-B orifice spool travel vector — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

A-B orifice area vector — Vector of valve opening areas
`[1e-10, 1e-05, 4e-05, 6e-05, .0001] m^2` (default) | 1-by-n vector

A-B orifice spool travel vector, ds — Vector of spool opening distances relative to fully closed position
`[0, .00125, .0025, .00375, .005] m` (default) | 1-by-n vector

A-B orifice pressure drop vector, dp — Vector of pressure differential values
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

A-B orifice volumetric flow rate table, q(ds,dp) — Array of volumetric flow rate values
`[-1e-08, 2.2e-08, 2.8e-08, 3.4e-08; -9e-06, .00015, .0002, .00024; -.00036, .00063, .00081, .00096; -.00054, .00094, .0012, .0014; -.00091, .0016, .002, .0024] m^3/s` (default) | M-by-N matrix

A-B orifice mass flow rate table, mdot(ds,dp) — Array of mass flow rate values
`[-1e-05, 1.7e-05, 2e-05, 2.6e-05; -.009, .0035, .0045, .0053; -.36, .7, .9, 1.06; -.54, 1.96, 2.5, 3; -.91, 6, 7.7, 9.13] kg/s` (default) | M-by-N matrix

A-B constant orifice area — Cross-sectional area for a constant orifice
`1e-4 m^2` (default) | positive scalar

A-B constant orifice pressure drop vector — Vector of pressure differential values for a constant orifice
`[-.1, .3, .5, .7] MPa` (default) | 1-by-n vector

A-B constant orifice volumetric flow rate vector — Vector of volumetric flow rate values for a constant orifice
`[-.0009, .0016, .002, .0024] m^3/s` (default) | 1-by-n vector

A-B constant orifice mass flow rate vector — Vector of mass flow rates for a constant orifice
`[-.9, 1.6, 2, 2.4] kg/s` (default) | 1-by-n vector

Spool position at maximum A-T orifice area — Spool offset from the neutral position for a fully open A-T orifice
`7.5e-3 m` (default) | positive scalar