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Infinite Flow Resistance (MA)

Perfectly insulated break in moist air network

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  • Infinite Flow Resistance (MA) block

Libraries:
Simscape / Foundation Library / Moist Air / Elements

Description

The Infinite Flow Resistance (MA) block represents a break in a moist air network. There is no mass or energy flow through the break. However, the moist air properties, specified by the Moist Air Properties (MA) block connected to the circuit, are the same on both sides of the break. Use this block to set the priority and initial target value to the differences in pressure, temperature, specific humidity, and trace gas mass fraction between port A and port B.

Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables and Initial Conditions for Blocks with Finite Moist Air Volume.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

Examples

Aircraft Environmental Control System

Aircraft Environmental Control System

Models an aircraft environmental control system (ECS) that regulates pressure, temperature, humidity, and ozone (O3) to maintain a comfortable and safe cabin environment. Cooling and dehumidification are provided by the air cycle machine (ACM), which operates as an inverse Brayton cycle to remove heat from pressurized hot engine bleed air. Some hot bleed air is mixed directly with the output of the ACM to adjust the temperature. Pressurization is maintained by the outflow valve in the cabin. This model simulates the ECS operating from a hot ground condition to a cold cruise condition and back to a cold ground condition.

Medical Ventilator with Lung Model

Medical Ventilator with Lung Model

Models a positive-pressure medical ventilator system. A preset flow rate is supplied to the patient. The lungs are modeled with the Translational Mechanical Converter (MA), which converts moist air pressure into translational motion. By setting the Interface cross-sectional area to unity, displacement in the mechanical translational network becomes a proxy for volume, force becomes a proxy for pressure, spring constant becomes a proxy for respiratory elastance, and damping coefficient becomes a proxy for respiratory resistance.

Ports

Conserving

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Moist air conserving port where the mass flow rate and energy flow rate are both equal to zero.

Moist air conserving port where the mass flow rate and energy flow rate are both equal to zero.

Extended Capabilities

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

Version History

Introduced in R2018a

See Also

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