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Valve Section with Rigid Shaft (IL-PB)

R2026b

Valve section with rigid shaft for hydromechanical valves

Since R2026b

  • Block icon

Libraries:
Simscape / Fluids / Isothermal Liquid / Valves & Orifices / Hydromechanical Valves

Description

The Valve Section with Rigid Shaft (IL-PB) block represents a section of a valve with a rigid shaft in the Hydromechanical Valves library. The valve section has rigid spacing along both the valve body and moving spool.

Port Relations

Ports F and B are hydromechanical valve composite ports that have valve_body, spool, and fluid nodes, where:

  • Position of F.valve_body relative to B.valve_body is equal to the value of the Valve body section length parameter.

  • Position of F.spool relative to B.spool is equal to the value of the Shaft length parameter.

  • When you clear Valve section contains liquid, the valve section does not contain liquid and does not use the nodes B.fluid and F.fluid.

  • When you select Valve section contains liquid, the block models liquid flow inside the valve section and:

    • The liquid volume is V=A∗L, where L is the value of the Shaft length parameter and A is the value of the Liquid cross-sectional area in valve section parameter.

    • You can enable the isothermal liquid port Af, which models a branching flow path, by selecting Enable port Af for the liquid in the valve section.

Block Sub-Components

The Valve Section with Rigid Shaft (IL-PB) block is equivalent to a composite component comprised of these Simscape Foundation and Fluids library blocks:

When you select Valve section contains liquid, the equivalent diagram is

system screenshot

When you clear Valve section contains liquid, the equivalent diagram is

system screenshot

Examples

Ports

Conserving

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Hydromechanical valve composite port that comprises three nodes:

  • B.valve_body — Position-based translational node along the valve body.

  • B.spool — Position-based translational node that moves along the spool.

  • B.fluid — Isothermal liquid node associated with the flow path inside the valve. If you select Valve section contains liquid, this node represents flow to and from an adjacent valve component. Otherwise, this node is unused.

Programmatic Use

Port: B

Hydromechanical valve composite port that comprises three nodes:

  • F.valve_body — Position-based translational node along the valve body.

  • F.spool — Position-based translational node that moves along the spool.

  • F.fluid — Isothermal liquid node associated with the flow path inside the valve. If you select Valve section contains liquid, this node represents flow to and from an adjacent valve component. Otherwise, this node is unused.

Programmatic Use

Port: F

Isothermal liquid conserving port that represents a branching flow path for the fluid.

Dependencies

To enable this port, select Valve section contains liquid and Enable port Af for the liquid in valve section.

Programmatic Use

Port: Af

Parameters

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Length of the body section of the valve.

Programmatic Use

Parameter: body_length

Length of the valve shaft.

Programmatic Use

Parameter: shaft_length

Whether the valve section contains liquid.

Programmatic Use

Parameter: contains_liquid
Values: "true" | "false"

Cross-sectional area of the liquid in the valve

Dependencies

To enable this parameter, select Valve section contains liquid.

Programmatic Use

Parameter: section_area

Option to enable the isothermal liquid port Af, which represents a branching flow path for the fluid.

Dependencies

To enable this parameter, select Valve section contains liquid.

Programmatic Use

Parameter: enable_liquid_port
Values: "true" | "false"

Whether to model the dynamic compressibility of the liquid. Dynamic compressibility affects the transient response of the system at small timescales. If you select this parameter, the pressure responds dynamically based on the accumulation of fluid mass in the volume. If you clear this parameter, the volume does not accumulate mass and the pressure response is instantaneous. Clearing this setting can improve simulation performance, but may have a negative effect on the simulation robustness. Only clear this setting for small fluid volumes or models with long simulation times.

Dependencies

To enable this parameter, select Valve section contains liquid.

Programmatic Use

Parameter: enable_dynamic_compressibility
Values: "true" | "false"

Pressure for the isothermal liquid at the start of the simulation.

Dependencies

To enable this parameter, select Valve section contains liquid and Enable fluid dynamic compressibility.

Programmatic Use

Parameter: p_init

Extended Capabilities

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

Version History

Introduced in R2026b