Turbulent Heat Transfer on Blunt-Nosed Bodies in Two-Dimensional and General Three-Dimensional Hypersonic Flow

Abstract

Recent results obtained for three-dimensional laminar boundary la3^ers are extended to the turbulent case. I t is shown that in the presence of highly cooled surfaces and of moderate Mach Numbers of the outer stream, the crossflow and the pertaining Reynolds stresses in a general three-dimensional turbulent boundary layer are negligible even for large transverse pressure gradients. A correlation due to Mager between two-dimensional compressible and incompressible turbulent boundary layers is extended to the problem in question. From a study of the transformation and of its implications, a rapid method for the analysis of the boundary-layer flow under the subject conditions is established. In the absence of general three-dimensional data, a comparison with experiments and with the predictions of other known analyses is carried out for several axiS3^mmetric configurations; the results of the method presented here exhibit good agreement with the data. The range of validity of the cold wall approximation for general three-dimensional problems is estimated qualitatively on the basis of recent measurements in laminar flow, the argument being that , for either zero or favorable streamwise pressure gradients, smaller threedimensional effects are to be expected in a turbulent boundary layer, as compared to a laminar layer.