An investigation of outdoor wind noise reduction by spherical windscreens

Abstract

Phelps [RCA Rev. 3, 203–212 (1938)] proposed that wind noise pressure fluctuations measured at the center of a spherical wind screen are the area averages resultant of the pressure fluctuations at the surface of the screen. If this hypothesis is applied to the steady state pressure distribution around a spherical windscreen, good agreement between data and theory should be achieved for turblence structures which are large compared to the windscreen. In this paper we report on experiments which extend the work done by Morgan (Ph.D. dissertation, University of Mississippi, 1992) on spherical windscreens. In this experiment, probe microphones placed within reticulated foam windscreens were used in conjunction with anemometers placed directly in the airflow near the windscreen to investigate the correlation between incident flow and the resulting pressure measurements throughout the foam.