Abstract: In order to improve the combustion efficiency of strut/cavity configurations in scramjet, numerical simulation was performed to study the reacting flow field of four different strut/cavity configurations, especially the effects of the combustor configurations on the kerosene combustion performance and the mass exchange rate of cavity. The numerical results show that the strut with rear wedge not only improves the mass exchange rate between the mainstream and cavity, but also creates a larger low-speed recirculation zone and combustion area downstream the strut. These factors increase the combustion efficiency of kerosene by 2.8%~5.8%. Although the application of dual-cavity cannot improve the mass exchange rate between the mainstream and cavity, it increases the low speed recirculation zone and combustion area, and increases the combustion efficiency by 4.5%~8.8%. Under the same inflow conditions, the total pressure recovery is similar in different strut/cavity configurations, and decreases with the stream Mach number increasing.

Key words: Scramjet； Strut；Cavity；Mass exchange rate

摘要： 为了提高超燃冲压发动机中支板/凹腔组合构型燃烧效率,通过数值仿真对采用支板/凹腔四种组合构型的燃烧室流场进行了研究,重点分析了不同组合构型对煤油燃烧性能以及凹腔质量交换特性的影响。结果表明:带后缘支板不仅能够提高主流与凹腔的质量交换律,并且能够扩大支板后部低速回流区及燃烧区域面积,从而使煤油燃烧效率提高2.8%~5.8%；采用双凹腔构型与采用单凹腔构型相比虽然不能提高单个凹腔与主流的质量交换律,但是增大了燃烧室低速回流区及燃烧区域面积,从而使煤油燃烧效率提高了4.5%~8.8%；在相同来流工况下,不同支板/凹腔组合构型燃烧室的总压恢复系数相近,随着来流马赫数增大总压恢复系数随之下降。 

关键词: 超燃冲压发动机;支板;凹腔;质量交换率 