Accession Number : AD0712237

Title :   STUDIES OF THE MECHANISM FOR THE FLOW-INDUCED CAVITY RESONANCE,

Corporate Author : DAVID TAYLOR MODEL BASIN WASHINGTON D C HYDROMECHANICS LAB

Personal Author(s) : Harrington,M. C. ; Dunham,W. H.

Report Date : 1960

Pagination or Media Count : 10

Abstract : Investigations of the excitation of cavity resonance by air flow were extended. Oscillations induced by flow across the mouth of box shaped cavities, with and without lips, were studied in water and air. This device consists of a box with a flexible side upon which a sinusodial variation in volume of the box is imposed, thus inducing velocities normal to the flow in the mouth of the box. Motion pictures of dye, injected upstream of the mouth, indicate that vortex formations are caused by the fluctuating velocity fields normal and tangential to the mouth. This vortex formation causes the turbulent mixing zone, containing free stream kinetic energy, to curve into and out of the box. The instability of the mixing zone causes alternating pressures in the box, which in turn may provide the excitation mechanism for resonance. Flexibility of the structure in water, and the compressibility of air, provide energy storage between cycles. In either case the amplitude of the peak-to-peak pressure changes determine the magnitude of the velocity variations normal to the flow in the mouth of the box. (Author)

Descriptors :   (*GAS FLOW, TRANSPORT PROPERTIES), (*OSCILLATION, FLUID FLOW), ENERGY, WATER, RESONANCE, VORTICES, TURBULENCE, PRESSURE

Subject Categories : Aerodynamics
      Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE