Supersonic Turbulent Boundary Layer Subjected to Step Changes in Wall Temperature

An investigation has been made into the effect of a step change in wall temperature on a turbulent boundary layerina supersonicowata Mach numberof2.3.Measurements of themean and turbulentow® elds were made. Theresultsshowthattherelaxation behaviorin general isslowexceptnearthewallwherethelogarithmicbehavior of the thermal and dynamical ® eld is unaffected. Perhaps more interestingly, it appears that the effect of strong heating on the velocity ® eld can be explained largely in terms of changes induced in the localuid properties, and speci® c compressibility effects appear to be small. A mixing length argument is suggested for scaling the Reynolds stresses and the comparison with measurements of the longitudinal Reynolds stress is encouraging.