Asymptotic investigation of heat transfer and skin friction in three-dimensional hypersonic rarefied gas flows

The three-dimensional hypersonic rarefied gas flow over blunt bodies is investigated in a transitional (from the free molecule to the continuum) flow regime. The problem is solved within the framework of the asymptotically correct thin viscous shock layer model by an asymptotic method developed for low Reynolds numbers. Simple analytical expressions are obtained for the Stanton number and the coefficients of skin friction and pressure on the windward surface of the body as a function of its geometrical characteristics and the free stream parameters. These solutions are represented in an invariant form that is independent of the choice of the system of coordinates. The limits of applicability of the asimptotic solution are estimated. It is shown that, when the Reynolds number tends to zero, the solutions for the Stanton number and the coefficients of skin friction and pressure approach to the values in the free molecule flow regime at unit accommodation coefficient.