Accession Number : AD0408075

Title :   MORE ON NOISE PRODUCED BY BOUNDARY-LAYER TURBULENCE,

Corporate Author : CALIFORNIA UNIV LOS ANGELES

Personal Author(s) : Powell,Alan

Report Date : 31 JAN 1963

Pagination or Media Count : 2

Abstract : The question of possible sound produced by stresses at a rigid surface is again discussed. It has been previously pointed out that these stresses are effective sources, being the reac tion to momentum fluctuations in a contiguous flow and with which the true sound sources are to be associated. There is no error in the orig inal general formalism, and no confusion need exist between hydrodynamic pressure and sound field pressure in the limits of very small sur faces (when net forces are to directly associated with dipole radiation) and of very large plane surfaces (when the surface pressures merely rep resent reflections of the quadrupole flow noise). (Author)

Descriptors :   (*TURBULENT BOUNDARY LAYER, NOISE), ACOUSTICS, MATHEMATICAL ANALYSIS, THEORY, OSCILLATION, ENERGY, REFLECTION, AERODYNAMIC CHARACTERISTICS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE