Accession Number : AD0436677

Title :   THE PHYSICAL PICTURE OF FLOW NOISE,

Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE)

Personal Author(s) : Skudrzyk, Eugen J. ; Haddle, Gillian P.

Report Date : APR 1963

Pagination or Media Count : 37

Abstract : The study of flow noise is based on exact computation, on model studies, and on statistical analysis. Measurements were performed in the water tunnel and with the aid of buoyant units. The effect of surface roughnesses was studied with a rotating cylinder. Special attention is given to radiated noise, since hydrophones used in underwater acoustics are relatively large and record the radiation noise only. Flow noise was reduced by tripping the boundary layer by coating the surface with sound-absorbent varnishes. It seems probable that flow noise can be reduced by reducing wall vibrations. (Author)

Descriptors :   (*UNDERWATER SOUND, WATER TUNNELS), (*NOISE, FLUID FLOW), STATISTICAL ANALYSIS, TURBULENCE, FOURIER ANALYSIS, INTEGRAL TRANSFORMS, HYDROPHONES, SENSITIVITY, BOUNDARY LAYER, CORRELATION TECHNIQUES, BODIES OF REVOLUTION, CYLINDRICAL BODIES, COATINGS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE