Turbulent boundary layers on a large flat plate at M = 4

Abstract

Transition positions, local skin-friction coefficients and boundary layer profiles measured in adiabatic flow on a flat plate are given. The data are for turbulent flow and cover a range of momentum-thickness Reynolds numbers of approximately 2500 to 25000. At high Reynolds number, skin-friction coefficients are well predicted by the relations of Spalding and Chi or Winter and Gaudet. Below a Reynolds number of roughly 10000 the results, though less reliable, seem to lie above these predictions; the higher values are corroborated by data from other sources. The inner parts of the velocity profiles follow a common law, well predicted by the correlation of Winter and Gaudet, and at high Reynolds numbers the velocity-defect profile of the outer layer agrees with a number of previous predictions. The outer parts of the profiles exhibit a wake component which decreases with decreasing Reynolds number and eventually vanishes. In respect of this behaviour, the compressible flow corresponds to an incompressible flow at a much lower Reynolds number.