[Rick]

Hi Everyone,

I am trying to simulate an incompressible fluid flow in a pipe. The problematic part of this simulation is that the outlet gets closed at some point during this transient simulation, and we have one inlet and no outlet. During this time, the inlet flow is supposed to inflate the walls by increasing the pressure inside the pipe. I tried to simulate this using an incompressible fluid but got convergence issues. After reading related posts here, I realized that making the fluid slightly compressible improves convergence. I did this using the following expression for the fluid density:

density=(Absolute pressure)/(R*Temperature)

Since the temperature is equal to 310K and absolute pressure should be near atmospheric pressure, to get the fluid density of 1050 kg/m3, the value of R needs to be equal to 0.3113.

Would you please let me know if this way of making the fluid slightly compressible causes any stability problems? I am asking this because my simulation can only be converged if the density and pressure URFs is less than 0.3.

Many thanks in advance!