[tangd]

I created a model in coodles using the existed pitzDaily mesh as template. I try to implement totalPressure and fix the temperature at inlet, while static pressure at outlet.

But there is no such boundary type I can use directly from FoamX, so I chose pressureInlet for inlet, and then changed pressure type from "fixedValue" to "totalPressure". I read from board and found that pressureTransmissive is helpful, so I applied pressureTransmissiveOutlet boundary type for outlet. I assigned 100bar to inlet totalPressure, and kept the outlet pressure setting from pitzDaily which is
OUT
{
type pressureTransmissive;
pInf 1e5;
lInf 0.3;
value uniform 1e5;
}

I expected that the pressure difference will result in mass flow inside the system then achieved a stable status. But from the plot Courant number over time, I observed the oscillation always occurring, it doesn't tend to stability. I think that the boundary condition was not correctly imposed. Can somebody give me some tips about how to set the boundary condition correctly? Thank you so much!