Implementation of CHIEF in MATLAB for prediction of sound radiated from arbitrarily shaped vibrating bodies

Abstract

The Boundary Element Method can be used to predict sound pressure levels radiated from an arbitrarily shaped vibrating body. Using the direct, indirect, and approximation formulation one can solve such an exterior acoustic problem. In this work, the direct formulation is chosen. The two major methods employed for implementation of this formulation are the Combined Helmholtz Integral Equation Formulation (CHIEF) and the Burton–Miller Method. It was decided that the CHIEF method would be the focus of this research. Using the CHIEF method as a guide, a computer simulation was developed that incorporates quadratic elements, calculates the sound pressure and sound power, is able to import surface velocities, and uses the program ideas as a preprocessor. This program was verified using theoretical models as well as experimental measurements conducted in the Western Michigan University Noise and Vibration Laboratory. This program was written in Matlab with the understanding that it can be processed on a personal computer.