Numerical calculation for a nonlinear acoustic impulse diffracted by a rectangular ledge

A computer model is developed for describing the diffraction of a nonlinear acoustic impulse signal by the irregularities of a perfectly rigid boundary. The model is based on the finite-difference method with the use of the MacCormack explicit scheme for solving the initial boundary-value problem formulated for a system of nonlinear equations of gas dynamics. The accuracy of the numerical calculations is estimated. The calculations are performed for the diffraction of the signal by ledges that occur at the irregular boundary. The results of the calculations are correlated with the estimates made by the Maekawa empirical theory. (C) 2000 MAIK "Nauka/Interperiodica".