VISCOUS AERODYNAMIC CHARACTERISTICS IN HYPERSONIC RAREFIED GAS FLOW. Research Report 48 (Revised)

Consideration is given to the problem of calculating viscous aerodynnmic characteristics of blunt bodies at hypersonic speeds and at sufficiently high altitudes where the appropriate mean free path becomes too large for the use of familiar boundary layer theory but not so large that tree molecule concepts apply. The complete Navier-Stokes equations are used as a model of the flow. In the stagnation region of blunt bodies they are reduced to ordinarv differential equations. which can be handled numerically. Examples are calculated for a sphere and a cylinder, with emphasis on surface shear stress. surface heat transfer rate. and shock detachment distance. These show that as the Reynolds nuinber decreases, the shear and heat transfer first increase above the value predicted by boundary layer theory at the same Reynolds number. and then fall off as the Reynolds number continues to drop. The maximum increase above boundary layer theory is about 20%. (auth)