Prediction of acoustic modal characteristics of two dimensional irregular shaped cavities by impedance mobility compact matrix (IMCM) approach

In this paper, the impedance and mobility compact matrix (IMCM) method for prediction of acoustic modal characteristics of two dimensional irregular cavities with the rigid wall boundary is presented. This method consists of discretizing the whole cavity into a series of subcavities either of regular or irregular shape. Continuity of both pressure and veloc- ity between adjacent subcavities is ensured using a virtual membrane with zero mass and stiffness. Mathematical formulation for acoustic cavities with the irregular shape has been explained in detail. A finite element model has been developed to calculate the acoustic natural frequency and mode shape. The proposed method is validated using a regular and irregular cavity and compared with finite element modelling results and available results in the literature.