Mean velocity scaling for compressible wall turbulence with heat transfer

The current state-of-the-art in accounting for mean property variations in compressible turbulent wall-bounded flows is the Van Driest transformation, which is inaccurate for non-adiabatic walls. An alternative transformation is derived, based on arguments about log-layer scaling and near-wall momentum conservation. The transformation is tested on supersonic turbulent channel flows and boundary layers, and it is found to produce an excellent collapse of the mean velocity profile at different Reynolds numbers, Mach numbers, and rates of wall heat transfer. In addition, the proposed transformation mathematically derives the semi-local scaling of the wall-normal coordinate and unifies the scaling of the velocity, the Reynolds stresses, and the wall-normal coordinate. (C) 2016 AIP Publishing LLC.