Acoustic model for far distance propagation coupling with CFD

Is the acoustic model for far distance propagation coupling with CFD can handle sound propagation over different media like air, water?

Direct prediction of far‐field noise in a CFD code is made somewhat impractical because of the meshing and timestep requirements.

• First, you must solve the time accurate compressible Navier‐Stokes equations. Accurately resolving the propagation of acoustic waves imposes timestep restrictions such that the Courant number is in the range of 1‐2 at most. This restriction can be highly costly. 
• Second, the CFD mesh must span all the way to the reception points with enough spatial resolution to directly resolve acoustic waves over the propagation distance with minimal to no numerical damping. 

These requirements do not make practical sense for many industrial applications. Practical predictions of farfield sound pressure levels are made by first starting with a time accurate CFD calculation of the near field region. Boundary and interior noise sources are taken from the transient CFD calculation, and used as input to an acoustic code using the Lighthill analogy. This method is however a one‐way approach that ignores coupling between acoustics and the flow field, and assumes the fluid behaves as an ideal gas.