Hypersonic drag and heat reduction mechanism of a new hybrid method of spike, multi-row discs and opposing jets aerodynamic configuration

Abstract

In this study, the drag force and aerodynamic heating reduction capacity of a novel combined spike root jet and multi-row disk (SRJ-MRD) model consisting of a blunt body, a spike, four aerodisks, and a counterflow jet was compared with geometric reported proposed in other studies. The proposed geometric model was numerically simulated using Reynolds-Averaged Navier–Stokes (RANS) equations with second-order spatial accuracy and the SST k-ω turbulence model. The flow was steady, compressible, and axisymmetric at Mach number 6. The primary attention of the present study has been focused on investigating the effect of the novel configuration on the flow field, shock-shock interaction, location of reattachment shock wave, and intensity of shock wave at the reattachment point. Besides, the effect of these parameters on the specifications of lift force and aerodynamic heating has been studied. Results showed that the existence of four aerodynamic discs (one conical aero disc and three smooth aerodisks) in the proposed model would guide the shear layer and separation shock wave upward, which causes the reattachment shock wave to occur on the blunt nose near the shoulder. Furthermore, the shock-shock interaction does not occur near the nose wall. In addition, the intensity of reattachment shock wave is reduced by the root opposing jet, and the low-temperature outlet will directly cool the front part of the blunt nose. It was found that the spatial location of maximum heat flux on the conical nose's wall is 68.90˚, denoting the positive effect of the proposed configuration on the reattachment shock wave, separation shock wave, and shock-sock interaction. To evaluate the new proposed configuration, the obtained results were compared with nine designs simulated by other researchers which used the same flow conditions and configuration (i.e., diameter, blunt body type, spike length, aerodisks diameter, location, and pressure ratio) but different control approaches. The results revealed that the drag coefficient and maximum heat flux were 0.2619 and 25.13 kw/m2, respectively. Compared to the results of the best design proposed by other researchers, i.e., spike configuration by applying lateral jet and spike tip, the present configuration shows a reduction in total drag coefficient (Cd,all) and maximum heat flux (Qmax) by 7.9% and 10.05%, respectively.