Accession Number : AD0276501

Title :   MEASUREMENTS OF THE CORRELATION BETWEEN THE FLUCTUATING VELOCITIES AND THE FLUCTUATING WALL PRESSURE IN A THICK TURBULENT BOUNDARY LAYER

Corporate Author : MICHIGAN UNIV ANN ARBOR

Personal Author(s) : WOOLDRIDGE,C.E. ; WILLMARTH,W.W.

Report Date : APR 1962

Pagination or Media Count : 1

Abstract : Turbulent motion in a thick (5 inch) boundary layer with zero longitudinal pressure gradient produced by natural transition on a smooth surface was studied. Measurements were made of the space-time correlations between the fluctuating wall pressure and the fluctuating velocities in the layer, and between the fluctuating wall pressure and the time derivative of the fluctuating velocity normal to the wall. At any height in the boundary layer the convection speed of the velocity disturbance which was correlated with the wall pressure disturbances was the local mean speed. The correlation of the wall pressure with the longitudinal velocity was opposite in sign to the correlation of the pressure with the velocity normal to the wall. The measurement of the pressure-velocity time-derivative correlation shows that most of the wall pressure is produced by velocity fluctuations near the surface. The correlation has a measurable value only in the inner 0.4 of the boundary layer. A vector field of the pressure-velocity correlation data is presented. (Author)

Descriptors :   *BOUNDARY LAYER, *FLUID FLOW, *ULTRAVIOLET RADIATION, CONVECTION, PRESSURE, SURFACES, SYNCHRONIZING SWITCHES, VECTOR ANALYSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE