# Mass Flow Rate Source (TL)

Generate constant mass flow rate

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

## Description

The Mass Flow Rate Source (TL) block represents an ideal
mechanical energy source in a thermal liquid network. The source can maintain a constant mass
flow rate regardless of the pressure differential. There is no flow resistance and no heat
exchange with the environment. A positive mass flow rate causes the fluid to flow from port
**A** to port **B**.

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

### Conserving

## Parameters

## Model Examples

## Extended Capabilities

## Version History

**Introduced in R2013b**