Controlled Volumetric Flow Rate Source (TL)

Generate time-varying volumetric flow rate

• Library:

• Simscape / Foundation Library / Thermal Liquid / Sources

• 

Description

The Controlled Volumetric Flow Rate Source (TL) block represents an ideal mechanical energy source in a thermal liquid network. The volumetric flow rate is controlled by the input physical signal at port V. The source can maintain the specified volumetric flow rate regardless of the pressure differential. There is no flow resistance and no heat exchange with the environment. A positive volumetric flow rate causes the fluid to flow from port A to port B.

The volumetric flow rate and mass flow rate are related through the expression

$$\dot{m}=\{\begin{array}{ll}{\rho }_B\dot{V}\hfill & \text{for }\dot{V}\ge 0\hfill \\ {\rho }_A\dot{V}\hfill & \text{for }\dot{V}<0\hfill \end{array}$$

where:

• $$\dot{m}$$ is the mass flow rate from port A to port B.

• ρ_A and ρ_B are densities at ports A and B, respectively.

• $$\dot{V}$$ is the volumetric flow rate.

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:

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

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

• ϕ_work is the isentropic work done on the fluid.

The isentropic work term is

$${\varphi }_{work}=\frac{\dot{m}\left(p_B-p_A\right)}{{\rho }_{avg}},$$

where:

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

• p_A is the pressure at port A.

• p_B is the pressure at port B.

• ρ_avg 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

V — Volumetric flow rate control signal, m^3/s

physical signal

Input physical signal that specifies the volumetric flow rate through the source.

Conserving

A — Source inlet

thermal liquid

Thermal liquid conserving port. A positive flow rate causes the fluid to flow from port A to port B.

B — Source outlet

thermal liquid

Thermal liquid conserving port. A positive flow rate causes the fluid to flow from port A to port B.

Parameters

Cross-sectional area at ports A and B — Area normal to flow path at inlet and outlet

0.01 m^2 (default)

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

Version History

Introduced in R2016a