Accession Number : AD0475286

Title :   STUDY OF THE EFFECTS OF HIGH INTENSITY SOUND ON TURBULENT INCOMPRESSIBLE FLOW.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Carlson, William C. ; Pittenger, Richard F.

Report Date : 1965

Pagination or Media Count : 60

Abstract : The effects of propagating a sonic disturbance without reflection in a direction parallel but contrary to flow, over the entire flow, were experimentally studied in a 10-cm by 10-cm square duct with a fluid velocity of 6.8 meters per second, or pipe Reynolds number of 4700. The effect was investigated over a range of sound frequencies of 300 to 1800 cps and sound pressure levels of 85 to 140 db re 0.0002 microbars. Sonic excitation reduced the low frequency components (below 300 cps) of the incoming turbulence. The turbulence reduction was greatest for a sound of frequency 700 cps and increased with increasing SPL. This reduction of incoming turbulence appears to retard transition to turbulence by reducing the amount of turbulence in air entering the duct thereby altering the turbulence profile without apparently changing the velocity profile. (Author)

Descriptors :   , (*INCOMPRESSIBLE FLOW, ACOUSTICS), AERODYNAMIC CHARACTERISTICS, SOUND TRANSMISSION, TURBULENCE, FLOW FIELDS, DUCTS, DUCT INLETS, BOUNDARY LAYER TRANSITION, LAMINAR FLOW, STABILITY, INTENSITY, PRESSURE GAGES, ANEMOMETERS, SOUND.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE