Asymptotically concordant continuum models ? the viscous shock layer (VSL) and the thin viscous shock layer (TVSL) ? are introduced for the investigation of heat-transfer and skin friction in the hypersonic rarefied gas flow over blunt bodies. Asymptotically correct shock and wall boundary conditions for these models are derived. For the VSL model, it is shown that at low Reynolds numbers it is essential to account for boundary condition terms related with shock and surface curvatures and effective wall conditions for the slip velocity and the temperature jump are proposed. The analytical solutions for heat-transfer, skin-friction and pressure coefficients are obtained by the asymptotic method for 2D and some 3D flows in transitional regime. The numerical simulation of the hypersonic flow over blunt bodies is carried out within the framework of VSL and TVSL models over a wide range of Reynolds numbers to determine the scope of applicability of continuum flow models.
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