Nonablative Dual-Jet Strategy for Drag and Heat Reduction of Hypersonic Blunt Vehicles

Abstract

Thermal protection systems (TPSs) and drag reduction have already garnered considerable attention in the field of hypersonic vehicles, and numerous research efforts have aimed to develop active control technology. In this study, a novel dual-jet strategy is proposed to enhance drag and heat flux reduction capabilities in hypersonic flows. First, an in-house code was validated sufficiently in simulating a hypersonic flow field. Then the flow features dominated by the novel dual-jet and the drag and heat flux reduction mechanism were discussed thoroughly. Based on that, the effects of the spike length and rear jet pressure ratio on the flow field are thoroughly investigated. The obtained results indicated that this novel strategy achieves excellent drag and heat flux reduction performance. The flow structure changes remarkably and the drag on the blunt body changes nonmonotonically once the spike length varies. Larger rear jet pressure can achieve better drag and heat reduction performance. Further, the way in which the rear jet affects the drag reduction and thermal protection is numerically analyzed. Interestingly, the constant mass flow rate of the rear jet, flow structure, and the drag and heat flux reduction capability are highly dependent on the rear jet pressure ratio, and lower rear jet pressure is conducive to drag reduction and thermal protection of hypersonic blunt vehicles.