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Hi everyone,

I want to simulate the shedding at a vortex flowmeter. I want to see how the vertices are propagated and if eventually plane waves come into being. This is obviously a compressible case. The problem is, if I simulate this body (with rhoPimpleFoam) initialized with the target velocity (in the whole internal field) of the operating point (say 6 m/s) I get two pressure waves starting from the body because the fluid "runs towards" the upstream wall (high pressure pulse) and "runs away" from the downstream wall (low pressure pulse). These are getting reflected at the walls and totally disturb my solution.
So my idea was to calculate an incompressible solution first, say with pimpleFoam, to obtain an appropriate velocity and pressure field around the body. Afterwards I want to continue with rhoPimpleFoam to take into account compressible effects.
However, I will need a rho field then. Theoretically I can calculate the density by means of pressure and temperature (assuming ideal gas). Can anyone help me how to carry that out practically? Can I do that somehow with foamCalc (havent found rho calculation yet) ? or is there any other possibility?

Thanks in advance