How can i parameter constant volume chamber (G) with inlets and oulets on simscape/simulink ?

Hi everyone,

i want to use gas chambers just to take into account volume effect on a gas circuit. So i need chambers with inlets and outlets. But the constant volume chamber on simscape gas domain have just inlets.

I wanted to know how can i use this block with inlets and outlets.

I tried to combine those chambers with controlled volumetric flow rate source on gas domain. It helps to ensure the gas's flow direction but not to discharge the chamber of a volumetric flowrate. Cause even if i give a negative value to the V port signal, it will just change the flow direction from port B to port A.

What would you have done ? Here an image to let you see.

Thanks a lot for your help.

Answer 1

[Yifeng Tang]

Hi Lina,

Simscape applies the pradigm of "acausal" modeling, meaning there is not a prescribed causality when the model is being built. In your case, it means you don't need to specify which one is inlet and which is outlet for this chamber. Either can be inlet or outlet, depending on the direction of flow and pressure differences during the simulation.

This applies to the source block as well. If you send a negative flow to the V port, it is mathematically equivalent to flipping the direction of A/B ports and sending a positive flow to V. No need to enforce which one is inlet or outlet.