Using the Inverse Boundary Element Method to Predict Sound Pressure in the Far Field

The inverse boundary element method (BEM) is a numerical procedure whereby sound pressure measurements in the near field are used to predict the vibration on the vibrating surface. After the vibration (or particle velocity for an opening) is determined, the sound pressure in the far field can be predicted using a forward BEM analysis. This paper will examine a particular example where the far field sound pressure was predicted for a generator set. The results indicate that the vibration predicted by the inverse BEM can be used to accurately predict the sound pressure as far away as 7 meters from the source.