Hi:

I am a beginner of CFX and i want to run a simulation of two phase flow. In the help document of CFX there is such a sentence that "Multiphase flows allow low speed compressibility effects to be modeled and you can mix compressible and incompressible fluids in one simulation."

But, in general, low speed flow can be regard as incompressible flow and compressible flow just mean high speed flow. So I want to know, in CFX ,low speed compressibility flow can simulate how fast velocity?

Thank you!

Hi Lily Compressible or incompressible is not determined by velocity only ( most will say mach>0.3 is compressible). The major item is about DESITY. For example, if there's a hot solid (say 1000 degC) stay still in still air, but you can imagine there'll be very large density variation around it due to hot air, so it's a compressible flow.

Nepal:

Thank you for your explaine, But i still have some puzzle that whether i can simulate high speed flow with mixture model.