Accession Number : AD0638215

Title :   GENERATION AND TRANSMISSION OF SOUND IN LIQUID-FILLED PIPE SYSTEMS.

Descriptive Note : Technical rept.

Corporate Author : HYDRONAUTICS INC LAUREL MD

Personal Author(s) : Phillips,O. M.

Report Date : 02 FEB 1962

Pagination or Media Count : 43

Abstract : The report is concerned with the generation and propagation of sound in pipe systems filled with moving liquid, and particularly with those fluid-dynamical aspects not considered in classical acoustical theory. The propagation down straight pipes containing turbulent flow is discussed, and under the usual practical circumstances, the classical theory is found applicable. When a short section of the pipe is lined with an elastically yielding lining, the sound attenuates very rapidly under optimum conditions while the mean flow is unhindered; it is suggested that such a device may be an efficient means of isolating sound pressure fluctuations. The roles of passive and active circuit elements in generating, reflecting and transmitting sound are considered. Among the elements discussed are junctions, bends, open ends, valves and pumps. A method of acoustical circuit analysis is set up that allows calculation of the pressure field and resonant frequencies for arbitrary geometries and configurations of elements, and some examples are given. (Author)

Descriptors :   (*SHIP NOISE, PIPES), (*SOUND TRANSMISSION, LIQUIDS), (*SOUND GENERATORS, LIQUIDS), FLUID DYNAMICS, PROPAGATION, ATTENUATION, TURBULENCE, ACOUSTICS

Subject Categories : Acoustic Detection and Detectors
      Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE