The present study numerically investigates the implication of air throttling on the combustion performance of ethylene fueled cavity-strut-based scramjet combustor using three-dimensional Large Eddy Simulation. With the augmentation of combustion performance by throttling being established, the effects of the mass flow rate of throttling and its location on the combustion performance are discussed. Our results indicate a strong interplay of flow rate and location of throttling on the combustion performance. Further, it is observed that with the introduction of air throttling there is enhancement in combustion efficiency due to the generation of pre-combustion shock train. The optimum mass flow rate of throttling enhances the mixing of fuel and air due to the shock-shear interactions increasing recirculation inside the cavity. Furthermore, the location of throttling essentially dictates the extent and intensity of the recirculation zone pinpointing a fixed zone and air throttling further upstream or downstream deteriorates the combustion performance. Optimum combustion efficiency is attained when air throttling is about 20% of the inlet mass flow rate at 83.6 mm from the cavity aft.

本研究使用三维大涡模拟数值研究了空气节流对乙烯燃料空腔支柱型超燃冲压发动机燃烧器燃烧性能的影响。随着节流增强燃烧性能的建立，讨论了节流质量流量及其位置对燃烧性能的影响。我们的结果表明流量和节流位置对燃烧性能有很强的相互作用。此外，观察到随着空气节流的引入，由于产生预燃烧冲击序列，燃烧效率得到提高。由于冲击剪切相互作用增加了腔内的再循环，节流的最佳质量流量增强了燃料和空气的混合。此外，节流的位置基本上决定了再循环区的范围和强度，确定了一个固定区域，而进一步上游或下游的空气节流会降低燃烧性能。当空气节流约为入口质量流量的 20% 时，在距空腔后部 83.6 毫米处，可获得最佳燃烧效率。