Flow Rate Source (IL)
Libraries:
Simscape /
Foundation Library /
Isothermal Liquid /
Sources
Description
The Flow Rate Source (IL) block represents an ideal mechanical energy source in an isothermal liquid network. The source can maintain the specified mass flow rate or volumetric flow rate regardless of the pressure differential. There is no flow resistance and no heat exchange with the environment. You specify the flow rate type by using the Flow rate type parameter.
Ports A and B represent the source inlet and outlet. The input physical signal at port M or V, depending on the flow rate type, specifies the flow rate. Alternatively, you can specify a fixed flow rate as a block parameter. A positive flow rate causes the fluid to flow from port A to port B.
The block icon changes depending on the values of the Source type and Flow rate type parameters.
Source Type  Flow Rate Type  Block Icon 

 Mass flow rate 

Volumetric flow rate 
 
 Mass flow rate 

Volumetric flow rate 

The block calculates the work performed on the fluid and includes the results in the simulation data log for information purposes:
$${W}_{mech}=\dot{m}\frac{{p}_{B}{p}_{A}}{\overline{\rho}}$$
$$\overline{\rho}=\frac{{\rho}_{A}+{\rho}_{B}}{2}$$
where:
W_{mech} is the mechanical work performed by the source.
$$\dot{m}$$ is the mass flow rate generated by the source.
p_{A} and p_{B} are pressures at ports A and B, respectively.
$$\overline{\rho}$$ is the average fluid mixture density.
ρ_{A} and ρ_{B} are fluid mixture density values at ports A and B, respectively. Equations used to compute the fluid mixture density depend on the selected isothermal liquid model. For detailed information, see Isothermal Liquid Modeling Options.
If the Flow rate type parameter is set to Volumetric
flow rate
, the block calculates the mass flow rate from the specified
volumetric flow rate:
$$\dot{m}={\rho}_{out}q$$
$${\rho}_{out}=\{\begin{array}{ll}{\rho}_{B},\hfill & q>0\hfill \\ {\rho}_{A},\hfill & q\le 0\hfill \end{array}$$
where:
ρ_{out} is the outflow density.
q is the volumetric flow rate.
For information on viewing logged simulation data, see Data Logging.
Assumptions and Limitations
There are no irreversible losses.
There is no heat exchange with the environment.
Ports
Input
Conserving
Parameters
Extended Capabilities
Version History
Introduced in R2020a