采用LES（大涡模拟）方法对强旋流环形通道入口速度突变后的回火特征进行了探究。通过模拟值和实验值的对比，验证了所用的大涡模拟方法。基于此模拟方法，研究了不同的旋流数下入口轴向流速突然降低，速度突变诱导的回火特性。研究表明，不同旋流数下都会出现核心区回火现象，而旋流数加倍的工况下核心区回火过程结束后还会出现燃烧诱导涡破碎回火现象。

The characteristic of flashback induced by suddenly reducing the axial velocity in a swirling annular channel was studied by LES. The numerical method was validated by comparing the results of simulation and experiment. Based on the validation, two additional cases with different swirl number were presented and investigated for the impact of swirl number on flashback. The core flashback was captured in both cases. Furthermore, the CIVB (Combustion-Induced-Vortex-Breakdown) flashback was observed in the case with swirl number doubled.

TK16

国家自然科学基金（NO.91441131,NO.91441119）