Low frequency wind noise contributions in measurement microphones

Abstract

In a previous paper [R. Raspet, et al., J. Acoust. Soc. Am. 119, 834–843 (2006)], a method was introduced to predict upper and lower bounds for wind noise measured in spherical wind-screens from the measured incident velocity spectra. That paper was restricted in that the predictions were only valid within the inertial range of the incident turbulence, and the data were from a measurement not specifically designed to test the predictions. This paper extends the previous predictions into the source region of the atmospheric wind turbulence, and compares the predictions to measurements made with a large range of wind-screen sizes. Predictions for the turbulence–turbulence interaction pressure spectrum as well as the stagnation pressure fluctuation spectrum are calculated from a form fit to the velocity fluctuation spectrum. While the predictions for turbulence–turbulence interaction agree well with measurements made within large (1.0m) wind-screens, and the stagnation pressure predictions agree well with unscreened gridded microphone measurements, the mean shear–turbulence interaction spectra do not consistently appear in measurements.