[remigius]

Hi,
In my work I am modeling a compressible flow in Fluent and I am wondering if I can use pressure density solver. In my model I have a time dependent flow where the Mach number could reach a value about 2. As its is a transient simulation I first try to run a model in steady state to have a good starting point for the transient analysis

• in steady state mode I have a Ma = 0.5 at inlet (i use pressure inlet boundary condition) and I use pressure based solver for calculations. The results I got are quite reasonable so it looks like the pressure based solver works well for this setup (beside that the fluent manual suggest to use pressure based solver to Ma <=0.3).
• Anyway, when I switch to transient calculations i expect an increase in Mach number in a model (for very short time) to values about 2. I tried to use a density based solver, but it has a huge problems with stability, convergence and results when a mach number and velocity in the domain increases.

So finally my question is: Do you have any experience from applying pressure based solver for high speed compressible flows in fluent? Can I look for reasonable results?

[sescobar]

Both pressure and density based solver have the capability of calculating compressible high Mach number flows. If you want further advice, please provide details on your problem set up.

[bhanuday.sharma]

In early days of ansys, the density based solver was designed particularly for compressible flows. but now a day both solver works fine in both compressible and in compressible flows. But inherently sometimes density based solver yields better results than pressure based