Evaluating the radiated sound at microphone location

Hi Everyone, 

First of all a very happy new year...!

If anyone has any information regarding this problem, please do help

I want to find the sound radiated  from a stator motor at some distance from it.

So I formed a solid sphere around the stator and used boolean operation to separate stator from the sphere, so that it will form a hollow section in the sphere where the stator was first placed.

Now I meshed the sphere with 3D finite elements and used M10 card to specify it.

Then I meshed the outer boundary of sphere with infinite elements (CACINF3) to absorb the acoustic property there. 

I provided the material property to it as PACINF. 

I don't know how the PACINF card works. I can't find the help file on it either.

Is the above method right? 

Please guide me on this

 

Have a good year ahead