Sound attenuation over long range ground-to-ground propagation paths

摘要

Rolls-Royce plc, Derby were commissioned by ESDU International plc to perform a series of tests to measure sound attenuation over distances up to 1.5 km. The tests were funded by government departments and industry in the UK. The sound source was a Rolls-Royce Avon single-stream jet engine. Weather data were measured at three stations. A balloon traverse was also carried out to measure atmospheric data profiles. The first stage of the analysis has been completed. A method of predicting the attenuation of sound as it propagates through a homogeneous atmosphere has been issued as a "Data Item" which is available commercially. The second stage of the exercise is the development and validation of a method that will predict sound attenuation in the presence of wind and temperature gradients. This paper describes the progress made so far and the path we intend to follow in the future.