Abstract: For the huge shock wave drag of hypersonic vehicles, the numerical method is adopted to analyze the drag reduction efficiency of a combinational model, which consists of the spike, lateral jet and blunt body. The lateral jet pushes the bow shock wave away from the spike, the combinational model has significantly weaker reattachment shock wave than the spiked blunt body. The drag coefficient of the combinational model is 33.52% lower than that of the spiked blunt body, thus verifying the excellent drag reduction efficiency of the combinational model. The influencing factors of the combinational model are analyzed. As the total pressure ratio of the lateral jet and the lengthdiameter ratio of the spike increase, the reattachment shock wave gradually weakens, thus improving the drag reduction efficiency. However, the change rate of drag reduction efficiency gradually decreases. As the nozzle moves downstream, the reattachment shock wave gradually increases to reduce the drag reduction efficiency, and the change rate of drag reduction efficiency gradually increases. In addition, the effects of the above factors on the flow characteristics and the position of peak pressure of blunt body are also studied in this paper.

Key words: Hypersonic vehicle, Spike, Lateral jet, Blunt body; Drag reduction