The near-wall temperature profile of turbulent boundary layers

Abstract

Solutions of t h e energy equation are presented for perturbed flows where the boundary layer displays s constant stress region near the wall. The analysis applies (0 flms with and without heat transfer, a t all Mach numbers. It is shown that the widely quoted forms of the velocity and temperature log-laws for low Mach number flows apply only in the limit of very low heat transfer rates. For compressible boundary layers with heat transfer, the relationships presented here can be used to determine the skin friction and heat transfer rate for perturbed boundary layers with a constant stress region near the wall. As a demonstration of the method, the skin friction and heat transfer -fficienta were determined for a Mach 2.3 turbulent boundary layer experiencing a step change in wall temperature.