An investigation of the fluctuations of the wall pressure and the wall pressure gradient beneath a turbulent boundary layer
Abstract
Fluctuations of the wall pressure and wall pressure gradient were investigated in a wind tunnel designed for acoustic measurements. The Reynolds number based on momentum thickness was 1400. It was shown that the diameter of the small transducers developed for these measurements is small enough to resolve the essential structures of turbulence. Correlation measurements of the pressure gradients and visual analysis of the time functions lead to a mean frequency and a mean wave length for characteristic high amplitude structures. The existence of these pressure structures explains the increase in the RMS value with decreasing transucer diameter and the characteristic feature of the probability density distribution. In the power spectrum there are indications of the existence of TollmienSchlichting waves.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 February 1979
 Bibcode:
 1979STIN...8014368S
 Keywords:

 Pressure Gradients;
 Turbulence Effects;
 Turbulent Boundary Layer;
 Wall Pressure;
 Wind Tunnel Walls;
 Anechoic Chambers;
 Power Spectra;
 Pressure Sensors;
 Probability Density Functions;
 TollmienSchlichting Waves;
 Fluid Mechanics and Heat Transfer