Controlled Pressure Source (TL)

Generate time-varying pressure differential

• Library:
• Simscape / Foundation Library / Thermal Liquid / Sources

• Description

The Controlled Pressure Source (TL) block represents an ideal mechanical energy source in a thermal liquid network. The pressure differential is controlled by the input physical signal at port P. The source can maintain the specified pressure differential across its ports regardless of the mass flow rate through the source. There is no flow resistance and no heat exchange with the environment. A positive signal at port P causes the pressure at port B to be greater than the pressure at port A.

The energy balance at the source is a function of the energy flow rates through ports A and B and the work done on the fluid:

${\varphi }_{A}+{\varphi }_{B}+{\varphi }_{work}=0,$

where:

• ϕA is the energy flow rate into the source through port A.

• ϕB is the energy flow rate into the source through port B.

• ϕwork is the isentropic work done on the fluid.

The isentropic work term is

${\varphi }_{work}=\frac{\stackrel{˙}{m}\left({p}_{B}-{p}_{A}\right)}{{\rho }_{avg}},$

where:

• ϕwork is the isentropic work done on the thermal liquid.

• pA is the pressure at port A.

• pB is the pressure at port B.

• ρavg is the average liquid density,

${\rho }_{avg}=\frac{{\rho }_{A}+{\rho }_{B}}{2}\text{.}$

Assumptions and Limitations

• There are no irreversible losses.

• There is no heat exchange with the environment.

Ports

Input

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Input physical signal that specifies the pressure differential across the source.

Conserving

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Thermal liquid conserving port. A positive pressure differential causes the pressure at port B to be greater than the pressure at port A.

Thermal liquid conserving port. A positive pressure differential causes the pressure at port B to be greater than the pressure at port A.

Parameters

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Area normal to the direction of flow at the source inlet and outlet. The two cross-sectional areas are assumed identical.

Extended Capabilities

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

Introduced in R2013b