Comparison of Re-Entry Flow Computations with High Enthalpy Shock Tunnel Experiments

Numerical calculation was applied to high enthalpy flows around re-entry bodies such as the HB-2 and two blunt cone models, which were already tested in the high enthalpy shock tunnel, HIEST in order to mutually evaluate the prediction capabilities between the two means for the aerothermodynamics data at the angle of attack of 0 degree. The numerical and experimental results showed good quantitative agreements each other in terms of the correlation between the viscous interaction parameter and axial force coefficient CA for the HB-2 model at the condition of stagnation enthalpy, H0 = 4 MJ/kg. The computed wall heat flux normalized by the one at the stagnation point on the HB-2 model increased in lower heat flux regions with increasing H0 because of the decrease in Mach number resulting in the thinner boundary layer. On the other hand, the HIEST one hardly varied, suggesting the possible deficiency of heat flux measurement for such regions in the HIEST. CA by the calculation for the blunt cone models was about 10% larger than the HIEST over at H0 = 7 MJ/kg, even though pressure coefficient distributions agreed well between the both, implying the problem of force measurement in the HIEST for higher H0 conditions. The numerical results for the HB-2 model at H0 = 12 MJ/kg showed that CA slightly increased due to the effect of chemical nonequilibrium flow, since the viscous interaction was enhanced by the recombination of O and N atoms within boundary layer.