Abstract: Air throttling is an effective method to facilitate flame stabilization. Flow structure in an ethylene-fueled scramjet combustor is studied by solving unsteady N-S equations and experiment. Results show that underthe inflow air condition Mach number 2.0，static temperature 530K，static pressure 0.1MPa，location of air throt. tling being 845mm from the entrance of the combustor，the cold flow field achieves stability. It is suitable for fuelinjected into the scramjet at 6ms and the hot flow is steady at 28ms after air throttling starts. The flow field pres.ents small cyclical oscillation，which has a small effect on the flow field with the cycle time 0.86ms. The calculat.ing data of wall pressure match the experiment data well，and the flow structure is illustrated comprehensively with numerical methods.

Key words: Scramjet；Air throttling；Flow structure；Oscillation

摘要： 空气节流可以有效地实现超燃冲压发动机燃烧室燃料的稳定燃烧，采用非定常数值模拟和地面试验研究了空气节流作用下乙烯燃料超燃冲压发动机的流场特性。结果表明:在燃烧室入口马赫数 2、静温 530K，静压 0.1MPa，845mm处节流条件下，冷流流场达到稳定所需时间较短，约为 2ms；在空气节流开始后的 6ms注入燃料实现发动机的起动点火是合适的； 28ms后燃烧流场稳定，流场呈现短周期的小幅振荡，周期约为 0.86ms，振荡对流场的影响很小；壁面压力数据的数值模拟结果与试验结果匹配良好，数值模拟更加全面地给出了流场结构信息。

关键词: 超燃冲压发动机；空气节流；流场结构；振荡