My Case is:

Induce an acoustic wave into a cavity filled with gas. The cavity maybe have hole connecting with outside. Analysises the acoustic wave resonance.

Does anyone know a commercial CFD software can apply to this case?

Thanks a lot

If there is no fluid flow you don't have to solve the transient NS-equation. Just use an plain acoustic code or Ansys or ... It should be possible to do with most cfd codes but it is a huge wase of computing time.

If you have a turbulent flow and an acoustic wave you can also forget the stuff because the transient pressure fluctuations from the fluid flow are some orders of magnitude larger than the pressure fuctuations from the acoustic waves.

FLUENT 5 has LES capability (or unsteady RANS) that you can use to compute the fluctuating pressure field. You can use the FLUENT data to compute overall sound pressure level. I understand several FLUENT users use this practical approach (using UDF) based on Lighthill's acoustic analogy to predict flow-induced noise, rather than relying upon full CAA.

You speake about pressure fluctuations within the flow field and not about sound.

Sound is something which is radiated to the far-field.

The pressure fluctuations in the area of acoustic sources do not need to produce any sound at all.