Numerical study on the effect of wind on sound propagation over sea surface by finite-difference time-domain method

摘要

In order to predict sound propagation from an aircraft flying above the sea to a receiver above ground, it is important to model the sound propagation over a rough sea surface with consideration of meteorological effects. Sound propagation over acoustically hard rough surfaces modeling sea surfaces have been calculated by the finite-difference time-domain method. In the calculation, both effects of scattering due to rough surfaces and refraction due to wind have been considered. The calculation results have been compared with those obtained by Green's Function Parabolic Equation (GFPE) assuming a flat ground with frequency dependent impedance. In this paper, we introduce the difference in sound propagation characteristics over a rough surface due to wind speed for several source heights and the prediction method of sound propagation over the sea from an elevated source is discussed.