Friction and Heat Transfer in the Boundary Layer on a Permeable Surface with Injection of Foreign Gas

A three-parameter (for energy, friction, and vorticity of turbulence) model is used to perform a numerical investigation of the boundary layer on a permeable surface under conditions of injection of a gas whose density and temperature differ from those of the gas of incident flow. The results obtained for the friction coefficient and Stanton number are compared with the available experimental data for the injection of helium, air, carbon dioxide, and Freon into a flow of heated air. It is demonstrated that the density ratio between the gas being injected and the gas of incident flow affects significantly the dependence of friction and heat transfer on the injection parameter.