Improvement of skin friction and heat transfer prediction theory of turbulent boundary-layer combustion of hydrogen

The theory for skin friction and heat transfer prediction to a compressible turbulent boundary layer including hydrogen/air combustion, proposed by Stalker, is improved in this paper. The original theory is modified through two aspects. One is to enhance the accuracy of the relation between hydrogen surface mass fraction and streamwise Reynolds number by directly integrating the Kármán momentum integral relation without local similarity hypothesis. Consequently, a new skin friction formula is established. The other is to change the Prandtl number from constant value of unity in the original theory to a variable computed based on the molecular kinetic theory. The performance of the improved theory is evaluated by an experiment with a flow on a flat plate and a designed two-dimensional numerical experiment. The skin friction and heat transfer predicted by the improved theory are found to be better consistent with the experimental or numerical experimental data than the original theory.