Abstract: In order to study integrated design of aerodynamic shape and stealth performance of the supersonic vehicle，the k-ω SST and multilevel fast multipole algorithm (MLFMA) is applied in this study and both the flow mechanism and scattering mechanism are analyzed with/without sawtooth. The aerodynamic performance and radar cross section (RCS) are obtained for the vehicle. The results show that RCS is reduced for the vehicle with sawtooth inlet lip by vertical polarization (VV) and horizontal polarization (HH) when frequency is 15GHz. A large number of small scale shock wave and vortex structure are found near the inlet lip. The normal flow of inlet is disrupted. Flow coefficient is the largest without sawtooth and it is smaller with the angle of sawtooth is 90°. The flow coefficient is the smallest when the angle of sawtooth is 45°. And inlet total pressure loss is the minimum without sawtooth. And the drag coefficient is smaller without sawtooth.

Key words: Stealth；Radar cross section；Aerodynamic shape；High resolution range profile；Flow coefficient；Total pressure coefficient；Drag coefficient；Supersonic vehicle；Inlet

摘要： 针对“X”型布局超声速飞行器气动外形与隐身性能一体化设计研究，采用标准k-ω SST湍流模型和多层快速多极子 (MLFMA) 数值计算方法，对比分析了有/无锯齿进气道唇口飞行器流动机理和散射机理，获得了有/无进气道唇口的气动性能和飞行器的雷达散射截面 (RCS)。研究结果表明:在入射频率15GHz时，采用锯齿外形进气道唇口的飞行器在垂直极化 (VV) 和水平极化方式 (HH) 时能够降低飞行器的RCS；在锯齿区域附近出现大量的小尺度激波和涡流结构，扰乱了进气道正常流动；无锯齿时，进气道流量系数较大，其次是锯齿角度为90°外形，锯齿角度为45°时进气道的流量系数相对最小，主要是因为锯齿角度45°时的进气道进口泄漏量相对较小；得到了无锯齿时进气道的总压损失最小，同时，无锯齿进气道唇口飞行器的阻力系数相对较小。

关键词: 隐身；雷达散射截面；气动外形；高分辨一维距离像；流量系数；总压恢复系数；阻力系数；超声速飞行器；进气道