[tenichols19]

I'm doing a compressible flow problem where my goal is to find the pressure drop across the flow system at a particular flow rate.

Things I know: The flow rate. I will either set the inlet and outlet to either a fixed velocity or mean velocity condition. But since it's a compressible flow problem I should probably implement a mass flow rate condition..

Things I don't know: The pressure drop across the system. I will be setting the the outlet to a fixed pressure 0 or atm, but I am unsure about the inlet.. I've heard the zeroGradient condition should work but I'm unclear about how it works.. If it has a zero gradient from the inlet patch to the internal patch, as the definition says in the documentation, how would a gradient be developed? I think I'm just reading this condition wrong.

Any help or advice would be appreciated.