[Xuekun]

Hello,

I just started to learn CFD for one week. And this is my first time posing a thread in this forum. I hope the experts here can help me with some confusions.


I am researching on the gas flow in multi-channel system, and inspecting the concentration and pressure distribution. For this problem, does it mean I have to use compressible gas simulation? Because if the density is constant, then there is no difference of concentration or pressure in the fluid channel, so no diffuse at all, is my understanding right?

If I want to inspect the diffuse of the concentration and pressure, what boundary conditions shall I define? I guess for the inlet boundary, constant velocity, mass flux rate and pressure are all fine? But what about the outlet?If I define pressure outlet to "static pressure", does it mean the velocity at the outlet is zero? Or outflow (don't know neither the velocity nor pressure at outlet) is a better choice?


I hope someone can help me with this ! Thanks a lot !