Heat Flux and Pressure Reduction Using Aerospike and Counterflowing Jet on Complex Hypersonic Flow

A numerical study on a reduction of aerodynamic heating and pressure by an active or passive control strategy has been conducted. Three-dimensional double ellipsoid models with aerospike or opposing jet are investigated. In numerical analysis, three-dimensional Navier-Stokes equations are solved by a finite-volume method, and hybrid LES/RANS turbulence model is used. The results show that the use of aerospike or counterflowing jet bring about an obvious decrease in pressure and heat flux values of the nose. However, both the pressure and heat flux appears an increase on body surface either for aerospike model or opposing jet model. For aerospike model, the aerospike will push the bow shock standing away from the first ellipsoid and creates an elliptical shaped recirculation zone, in which the pressure and heat flux keep at a low level. After that, the shear layer will reattaches to the shoulder and creates the peak value of the heat flux and pressure. For opposing jet model, the counterflowing jet flows out the nozzle and pushes the bow shock away from the nose. Meanwhile, the jet flow is pushed back by the freestream and reattached to the ellipsoid shoulder surface. Then, the heat flux and pressure peaks are created by reattachment. These separation and reattachment lead to the ups and downs of the surface pressure and heat flux.