The Acoustic Performance of a Cranked Barrier: An Approximate Integral Formulation

The problem of sound diffraction by a cranked barrier due to a single source has been investigated. The theoretical models have been extended to consider the case of sound diffraction by a finite length cranked barrier. The proposed method has been based on the boundary integral formulation. The sound field on barrier surfaces was estimated by adopting an image source method using appropriate boundary conditions. The estimated sound field on barrier surfaces has then been substituted into a set of boundary integral equations. An approximate solution has been derived to predict sound diffraction by an acoustically hard cranked barrier placed over a flat ground. The approximate solution reduces the computational time for calculating the sound field around a three-dimensional cranked barrier for practical applications. Published data and the developed ray model have been used to compare with the approximate scheme. Measurements in an anechoic chamber have been conducted to validate the proposed formulations. Satisfactory comparisons have been obtained between the theoretical predictions and experimental data.