RESEARCH IN BOUNDARY LAYER OSCILLATIONS AND NOISE

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.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1964
Accession Number
AD0431190

Entities

People

  • J. L. Willis
  • M. K. Bull

Organizations

  • University of Southampton

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Space

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Boundary Layer Flow
  • Convection
  • Flow
  • Frequency
  • Frequency Bands
  • Instrumentation
  • Layers
  • Pressure Measurement
  • Probability
  • Probability Distributions
  • Resonant Frequency
  • Turbulent Boundary Layer
  • Turbulent Flow
  • Vibration
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Fluid Mechanics and Fluid Dynamics.
  • Regression Analysis.

Technology Areas

  • Space