Ansys Learning Forum Forums Discuss Simulation Fluids Acoustic pressure calculation LES + FH-W Reply To: Acoustic pressure calculation LES + FH-W

Federico
Ansys Employee

Hello, 

regarding LES, scale resolving simulations are really sensitive to grid sizing and hence the mesh must be finely tuned to what you are looking to resolve. Questions you should be asking yourself:

  • What it you grid size in the region of interest? How does it relate to the acoustics that you expect to find?
  • Related: given the time step size, what is your acoustic Courant number? You should aim for a Courant number <= 1. Your timestep should also be fine enough to resolve the expected pressure signals with highest frequency. A good rule of thumb is to have at least 10 points for a half-period of the pressure signal with highest frequency.

Regarding FWH, what is your acoustic source and where is your acoustic receiver? Typically, a scale resolving simulation (such as LES) is run to establish the flow with high accuracy and then followed with FWH model. I would need more information on how exactly you set this up you give you more assistance.

I hope his helps!