On The Modelling Of Cavities At Low Frequencies With The BEM

Many transducers (e.g. microphones) consist of a moving part facing the exterior on one side and facing a closed cavity on the other. In order to obtain and solve a model of such transducers, a fully coupled model can be used and the performance of this model will rely of the performance of the sub-models being coupled.

Previous work has revealed that the performance of an interior lossless BEM formulation concerning a cavity with rigid walls can pose a limit on the accuracy of a fully coupled model of the transducer – in particular when including viscous and thermal losses in the cavity. This paper investigates the accuracy of a lossless acoustic BEM formulation for cavities with rigid walls at low frequencies and addresses possible solutions for restoring accuracy.