{"id":167562,"date":"2022-03-21T17:08:50","date_gmt":"2022-03-21T17:08:50","guid":{"rendered":"\/forum\/forums\/topic\/harmonic-acoustic-absorption-surface\/"},"modified":"2022-03-24T19:15:59","modified_gmt":"2022-03-24T19:15:59","slug":"harmonic-acoustic-absorption-surface","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/harmonic-acoustic-absorption-surface\/","title":{"rendered":"Harmonic Acoustic – Absorption Surface"},"content":{"rendered":"
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Hello, <\/p>\n

I am trying to perform analysis which evaluates how much energy is absorbed by acoustic panel in the circural tube (see pic 1). The acoustic panel consists of mineral wool glued to perforated plate. Holes in perforated plate lead to very difficult mesh, so I wanted to simplify it by removing the perforated plate from model and applying the Absorption Surface boundary condition to a surface where mineral wool and air domain meet. This BC should tell how much energy is ,,absorbed" (not really absorbed, because we know steel plate cannot absorb acoustic energy) by perforated plate itself. The problem is that even though I apply the Absorption Surface to the interface of both domains, SPL doesn't get lower when it goes through (see pic 2).<\/p>\n

I just want to find a way how to avoid meshing holes in perforated plate and how to apply some BC to interface between mineral wool and air (where the perforated plate is located) instead (in this case the mesh wouldn't be so difficult but I am also making more difficult model where meshing of holes would lead to milions of elements). I also dont know if Absorption Surface is correct boundary condition to use in this case.<\/p>\n

I would like to know what is the problem in my analysis and why isn't SPL lowering.<\/p>\n

Any help will be appreciated.<\/p>\n

Thanks in advance,<\/p>\n

J<\/p>\n

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