I am using Phoenics to simulate a pulsatile air flow in a pipe. The velocity at entrance follows a sinusoidale shape. I want to know if it is possible to see the pressure wave propagation inside the pipe when I use an incompressible flow, and how to deal with if not.

thanks for any advice.

In incompressible flows, pressure waves travel instantaneously. You can see the waves during the convergence process, but it is a numerical result without physical meaning.

Hope this helps,

hey carlos

Do you mean that I must use compressible flow. In our case, the flow is turbulent, but we have no idea about mach number.

thank you for your contribution. tah

No, what I mean is that you cannot use a constant density. You have to develop an expression for your density that should be a function of pressure. PHOENICS has many options of density expressions, but I do not know if any of them can be what you need. If I were you, I would try to use a density that is calculated from the ideal gas equation as a first approximation (it is one of PHOENICS options) just to try to see the waves. Then, having success, I would try something more specific. Watch out if your flow is supersonic. You should take special care in this case. Hope this helps you.

Hi carlos

thank you for explanation. but As Iam a beginner in CFD modeling, is there any diffrence between your suggestion ( variable density) and compressible flow.

best regards, tah

U should study thoroly the flows then u can do the modelling

i want to know that how this pressure wave(sound wave)can be conserved and how it can be converted in to electric current(energy).