Turbulence effects on sound propagation from an elevated source

Abstract

In a study of sound propagation from an elevated source, the turbulence effects appeared to be much smaller than was expected from Daigle's paper on turbulence effects on sound propagation with source and receiver close to the ground [J. Acoust. Soc. Am. 65, 45–48 (1979)]. In this paper, we describe the application of an atmospheric model for turbulence developed by Johnson and Rasper [J. Acoust. Soc. Am. Suppl. 1 77, S92 (1984)] to the refractive turbulence effects theory of Clifford and Lataitas [J. Acoust. Soc. Am. 73, 1545–1550 (1983)]. This theory predicts the reduction of turbulence effects observed in the noise study for elevated sources. The implications of this study for aircraft noise measurements will be briefly discussed.