An Energy Boundary Element Formulation for Predicting the Acoustic Field Around a Vehicle at High Frequencies Due to Airborne Noise Sources

An Energy Boundary Element Analysis (EBEA) formulation is presented for calculating sound radiation from a source with arbitrary shape at high frequency. The basic integral equation for the EBEA is derived including a half-space boundary condition. The time and frequency averaged acoustic energy density and acoustic intensity constitutes the primary variables of the new formulation, and the corresponding Green’s functions are derived. The governing equations for the EBEA are established and the numerical formulae for the coefficients of the system matrix, the acoustic energy density, and the acoustic intensity are derived using a Gaussian quadrature. The EBEA formulation and the corresponding numerical implementation are validated by comparing EBEA results to test data for the acoustic field around a vehicle that originates from an airborne noise source. Good correlation is demonstrated between numerical predictions and test data.