SKIN FRICTION LAW FOR COMPRESSIBLE TURBULENT-FLOW

An algebraic skin-friction law is derived for adiabatic, compressible, equilibrium, turbulent boundary-layer flow. An outer solution in terms of the Clauser defect stream function is joined to an inner empirical expression composed of compressible laws of the wall and wake. The modified Crocco temperature-velocity relationship and the Clauser eddy viscosity model are used in the outer solution. The skin-friction law pertains for all pressure gradients in the incompressible through supersonic range and for small pressure gradients in the hypersonic range. Excellent comparisons with experiment are obtained in the appropriate parameter ranges.