Heat and Mass Transfer in Turbulent Boundary Layers

Abstract

This chapter investigates the heat and mass transfer processes in turbulent flow of liquid or gas under conditions of high heat flows, high temperatures, and high flow velocities. In engineering practice, extensive use of purely empirical methods is made for calculating drag and heat transfer in compressible gaseous turbulent boundary layers based on the introduction of some version of the “reference” temperature. The coefficients of the drag and heat transfer are only weakly dependent on the Reynolds number. This fact permits the limiting law, accounting for nonisothermality and mass transfer, to be extended with a satisfactory degree of accuracy to flows with finite Reynolds numbers. The main ideas of the theory of limiting laws are described and the limiting equations for friction and heat transfer are derived for the general case. The turbulent boundary layers in compressible flow are analyzed. The chapter analyzes the effectiveness of film cooling for different methods of introducing the coolant.