Accession Number : ADA221358

Title :   Physical and Computational Investigation of the Wall Pressure Fluctuations ina Channel Flow.

Descriptive Note : Final rept. Jan 88-Jan 90,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Horne, Michael P.

Report Date : 26 APR 1990

Pagination or Media Count : 174

Abstract : Wall pressure fluctuations within an equilibrium rectangular channel flow geometry were investigated. The overall objective of this investigation was to obtain experimentally for the first time, the statistical properties of the wall pressure fluctuations for a generic turbulent flow within a rectangular channel and to directly compare the results with those obtained from a full solution to the Navier-Stokes equations via Direct Numerical Simulation (DNS). For both the physical and computational experiments, serious limitations on the quality of the results were identified related to facility generated noise, transducer resolution, Reynolds number effects and constraints imposed by the computational technique. An extensive data base was obtained from the physical experiment. Profiles for the means and fluctuations components of the streamwise velocity were obtained at a number of spanwise locations and served to establish the existence of equilibrium flow conditions over a range of Reynolds numbers. An array of flush-mounted pressure transducers was utilized to measure the two point spectral characteristics in the stream-wise direction. A unique signal processing scheme was developed and used to cancel facility generated noise which resulted in new information being recorded at low frequencies for the Reynolds numbers investigated. Keywords: Noise cancellation; Wall pressure; Direct numerical simulation; Turbulent flow; Hydrodynamic flow noise. (JHD)

Descriptors :   *CHANNEL FLOW, *NOISE REDUCTION, *TURBULENT FLOW, CANCELLATION, CHANNELS, COMPUTATIONS, DATA BASES, DOWNSTREAM FLOW, EQUILIBRIUM(GENERAL), DIGITAL SIMULATION, FLOW, FLOW NOISE, HYDRODYNAMICS, LOW FREQUENCY, MOUNTS, NAVIER STOKES EQUATIONS, PRESSURE, PRESSURE TRANSDUCERS, RECTANGULAR BODIES, REYNOLDS NUMBER, SIGNAL PROCESSING, SOLUTIONS(GENERAL), STATISTICS, VARIATIONS, VELOCITY, WALLS.

Subject Categories : Fluid Mechanics
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE