Sound propagation over screened ground under upwind conditions

Abstract

A screen on an absorbing ground is investigated experimentally and theoretically under upwind conditions. The experimental data are the result of scale model experiments in a 1:25 scale model. The sound propagation is measured using a triggered spark source with signal spectrum averaging in the frequency domain. The meteorological data representing the wind conditions have been determined by means of hot-wire anemometry in positions on both sides of the screen as well as directly over the screen. The theoretical model used for comparison is a hybrid approach. The sound field without a barrier is determined by means of numerical integration of a Hankel transform solution for a stratified atmosphere [like a fast field program (FFP) but taking the near field into account]. This solution is used on both sides of the screen and is combined with a screen diffraction calculation. Results from the calculation model are able to explain the overall tendency in the experimental results.