Erik Kostson
Ansys Employee

You will not be able to predict for a solid 3D structure since the absorption is a thermal and viscous effect that is caused say for instance by the coupling of acoustic and elastic waves in porous material so quite complex - you can predict this though to certain extents if you use a an equivalent model - so know the porosity, fluid resistivity,....,for JCA or fluid resistivity for Delany-Bazley equivalent model. See the help manual for a range of validity for these models which assume a rigid skeleton (JCA), but also Bazley can be used for very soft mineral wool type of absorbers say like those of rockwool type found in acoustic applications. So they can be used to account for absorption is foam like material to a certain extent

To assign these properties go to engineering data:

Hope this helps