某型斜流驻涡燃烧室火焰筒冷却结构优化研究

Cooling Structure Optimization of Flame Liner in a Mixed-flow Trapped Vortex Combustor

本文对某原型斜流驻涡燃烧室进行数值模拟,再将冲击/气膜+多斜孔复合冷却结构应用于该火焰筒进行优化。研究发现燃烧室内形成双涡结构:主涡内气流流速较低,燃气在主涡回流;副涡隔绝了主流和主涡,提高了火焰稳定性。原型火焰筒总冷气量占比为28.83%,且凹腔前壁存在局部高温区。冷却结构优化后,火焰筒的总冷气量减少到21.9%,冷气在凹腔前壁近壁区形成了有效的气膜保护,减弱了主涡内气流的掺混强度,壁温显著降低且分布更为均匀。

In this paper, a prototype mixed-flow trapped vortex combustor was numerically simulated, and an impingement-film and inclined multi-hole cooling structure was applied to the flame liner for optimization. The results show that a dual counter-rotating vortex trapped in the combustion chamber. The flow rate is low and the gas flows back in the primary vortex. The secondary vortex isolates the mainstream from the primary vortex and improves the stability of the flame. The proportion of cooling-air in the prototype flame liner is 28.83%, and hot spots exist on the fore-wall.After the cooling structure is optimized, the cooling-air in the flame liner is reduced to 21.9%. The cooling-air forms an effective film protection near the fore-wall, weakening the mixing intensity of the airflow in the primary vortex. The wall temperature is significantly reduced and has a more uniform distribution.