Properties of wall shear stress fluctuations in a turbulent duct flow
Abstract
Measurements of wall shear stress fluctuations have been made in a fully developed turbulent duct flow, using a surface heat transfer gauge. Measurements, made over a moderate Reynolds number range, include RMS values, probability density functions, spectra, and zerocrossing frequencies of the wall shear stress fluctuation. The ratio of RMS of the fluctuation to the mean value of the wall shear stress is found to be about 0.25. The zerocrossing frequency computed from the measured spectra using the relation derived by Rice for a Gaussian process is found to be a good approximation to the measured value, although the measured probability density function is not Gaussian. The zero crossing frequency and spectra of wall shear stress fluctuations appear to scale with outer variables for asymptotically large Reynolds numbers.
 Publication:

ASME Journal of Applied Mechanics
 Pub Date:
 September 1977
 Bibcode:
 1977ATJAM..44..389S
 Keywords:

 Ducted Flow;
 Power Spectra;
 Probability Density Functions;
 Shear Stress;
 Turbulent Flow;
 Unsteady Flow;
 Asymptotic Methods;
 Flow Measurement;
 Fluctuation Theory;
 Heat Transfer;
 Mass Transfer;
 Reynolds Number;
 Fluid Mechanics and Heat Transfer