Accession Number : AD0431190


Title :   RESEARCH IN BOUNDARY LAYER OSCILLATIONS AND NOISE


Descriptive Note : Technical documentary rept.


Corporate Author : SOUTHAMPTON UNIV (UNITED KINGDOM)


Personal Author(s) : Bull, M K ; Willis, J L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/431190.pdf


Report Date : Feb 1964


Pagination or Media Count : 61


Abstract : Experimental data are presented on the r.m.s. levels, frequency spectra, probability distributions and space-time correlations of the pressure field as a whole, and in narrow frequency bands, for turbulent layers on smooth surfaces. General qualitative effects of a surface discontinuity on the r.m.s. pressure and frequency spectrum are given. An empirical representation of the space-time correlation pattern of the pressure field is developed for the purposes of structural response calculations. A general program for the study of a mechanism of boundary layer turbulence is presented along with a discussion of the testing and analyzing instrumentation. An analytical method is presented for the prediction of the power spectral density of panel response to boundary layer and siren excitation. An empirical equation is developed relating the acoustic power output from a unit area of a (large) surface subject to turbulent boundary layer flow to the aerodynamic flow parameters.


Descriptors :   *TURBULENT BOUNDARY LAYER , *AERODYNAMIC CHARACTERISTICS , *AERODYNAMIC NOISE , VIBRATION , EXCITATION , SURFACES , PRESSURE , INSTRUMENTATION , OSCILLATION , ACOUSTIC PROPERTIES , NOISE GENERATORS


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE