SOME RESULTS OF EXPERIMENTAL INVESTIGATIONS OF THE SURFACE PRESSURE FIELD DUE TO A TURBULENT BOUNDARY LAYER.

Abstract : Experimental results for the space-time correlations of the fluctuating pressure field of a turbulent boundary layer are given, and an empirical representation of the pressure field suitable for structural response calculations is presented. Variation with Mach number of r.m.s. pressure as a function of skin friction is given for Mach numbers up to about 1.6. The probability distribution of the pressure fluctuations at a fixed point in the field is found to approximate closely to Gaussian. The acoustic power output from a boundary layer on a larger boundary surface is obtained. Spectra of boundary layer noise in tow jet aircraft are presented and compared with the spectrum of the boundary layer excitation. (Author)