Questions regarding Vibro-Acoustics simulation using SOL 108 in Simcenter Nastran


Hi, I am doing a Vibro Acoutics simulation problem and have few questions about that:


Background of the simulation problem:

A monopole source is placed inside a box having a hole or holes. (Attached figure of the setup). Domain A is inside domain (inside box), domain B is outside domain (outside box) and to external surface of domain B is applied an AML BC. The bottom face of box is also fixed BC. There is an array of microphones at certain distance from AML region that measures the acoustic pressure. 


1. Is it appropriate to apply AML like this or should it only be applied on a convex surface.

2. Is it good to model inside (A) and outside (B) acoustic domain as one (continuous) in this case or should they be modeled seperately and glued together at the interface using acoustic continuity.

3. Should the mics be kept inside the outside acoustics domain (WIll it change the results as compared to keeping them outside AML BC)


I want to get Acoustic pressure at microphones ultimately and put them in Matlab code that uses delay and Sum Beamforming to predict the location of the hole/holes, but so far the mic pressures that I am getting is not giving me right results (Hole location) when I enter them into the matlab code.


Am I doing something wrong as I believe the code is right and there is something wrong with the simulation results? Or is there any way to validate the mic pressure results (I could not find any analytical solution for this problem).

I would appreciate any help !



Ashwani Thakur.