Application of head's entrainment method to the prediction of turbulent boundary layers and wakes in compressible flow

Abstract

Details are given of an adaptation of Head's entrainment method to compressible flow which has been in use in R.A.E. since 1967. This version is a simplification of an earlier application of the entrainment method in compressible flow, and one which is believed internally consistent and reliable over a wider range of Mach numbers than its predecessor. The main feature of the method is that it has been 'tied' to the flat plate skin-friction correlation of Spalding and Chi, so that at least its accuracy in zero pressure gradient is assured. Other innovations are the introduction of a simple explicit two-parameter approximation to two more elaborate but implicit skin-friction relations, and the extension of the method to treat aerofoil wakes. Comparisons with experiment are shown to support these extensions. Finally, in Appendices, some further but as yet untried refinements of the method are presented and, in particular, a tentative treatment of compressible flows with heat transfer is given.