The Acoustic Field in a Closed Space Behind a Rectangular Simply Supported Plate Excited by Boundary Layer Turbulence

摘要

An analytic solution is obtained for the acoustic pressure statistics in a closed rectangular shaped cavity behind a simply supported, rectangular plate excited by boundary layer turbulence. The contribution of the cavity acoustic pressure is neglected as contributing to the plate excitation, leaving only the turbulent pressure fluctuations as the exciting force. The mathematical model for the turbulent pressure statistics is based on that of Corcos, which agrees well with experiment. A byproduct of this analysis is an analytic solution for the turbulent flow excited plate vibration velocity statistics. The plate velocity and cavity acoustic pressure statistics are expressed in the form of cross power spectral densities and power spectral densities. Dimensionless forms of the plate velocity spectral density and cavity acoustic pressure spectral density are developed. The dimensionless plate velocity spectral density and dimensionless cavity acoustic pressure spectral density were computed, by means of a digital computer, for selected values of dimensionless input parameters. From these computed dimensionless spectra, the effects of major parameters on the plate velocity spectral density and the cavity acoustic pressure spectral density were determined. (Author)