The drag of a compressible turbulent boundary layer on a smooth flat plate with and without heat transfer

The theoretical treatments given by earlier authors are classified, reviewed and where necessary extended; then the predictions of twenty of these theories are evaluated and compared with all available experimental data, the root-meansquare error being computed for each theory. The theory of van Driest-II gives the lowest root-mean-square error (11.0%). A new calculation procedure is developed from the postulate that a unique relation exists between c f F c and RF R where c f is the drag coefficient, R is the Reynolds number, and F c and F R are functions of Mach number and temperature ratio alone. The experimental data are found to be too scanty for both F c and F R to be deduced empirically, so F c is calculated by means of mixing-length theory and F R is found semi-empirically. Tables and charts of values of F c and F R are presented for a wide range of M G and T S / T G . When compared with all experimental data, the predictions of the new procedure give a root-mean-square error of 9.9%.