On The evaluation of radiated sound field of Engine covers

Acoustical performance of many NVH systems is evaluated by computing the radiated noise of such systems. Although the computation of relevant acoustical quantities such as the radiation efficiency and sound power can be performed by using approximate method such as the Rayleigh integral method, in most instances rigorous methods such as the boundary element method is preferred. Unfortunately the boundary element method for radiation problems fails at the eigenfrequencies associated with the interior cavity. Additionally, in most instances the acoustical performance is needed to be evaluated over a range of frequencies and in a traditional boundary element system this evaluation is performed independently at each discrete frequency. In this presentation, issues associated with the accuracy and efficiency of these solutions are addressed by investigating the solution of progressively more complex industrial problems.