RQL燃烧室流场特性研究

Investigation of Flow Field Characteristics in RQL Combustor

针对环形富油燃烧-焠熄-贫油燃烧(Rich burnQuench-Lean burn)燃烧室内的焠熄掺混,利用激光PIV(粒子图像速度仪)对几种冷态工况下的流场进行激光可视化分析研究,考察了射流主流通量比和主流雷诺数变化对燃烧室头部流场及下游旋流的影响规律。实验中喷嘴出口主流和焠熄射流均使用25℃空气,同时维持燃烧室内压力恒定。研究表明:当维持主流雷诺数不变时,增加焠熄射流动量通量比,回流区尺寸发生变化,长度减小宽度增加,同时回流区形状逐渐从锥形向柱形发展;焠熄射流会影响下游流场的旋流,维持主流雷诺数不变的情况下,随着动量通量比的增加,焠熄射流孔下游的旋流逐渐被破坏;而维持动量通量比的情况下,主流雷诺数对回流区形状尺寸和焠熄孔下游旋流无明显影响。

Visualization investigation with PIV(Particle Image Velocimetry) for an annular RQL(Rich burn-Quench-Lean burn) combustor was conducted under non-reacting conditions. The influences of momentum flux ratio and main flow Reynolds number on the flow field and downstream swirl flow were investigated. The experiment was carried out at atmospheric pressure condition with both mainstream and quenching jets with temperature of 25℃. Several distinct results were concluded. With a constant mainstream Reynolds number,increase in momentum flux ratio results in significant change of the recirculation zone size,with the length decreasing and the width increasing,leading to the shape of recirculation zone altering from conical to cylindrical.(Quenching jet also influences the downstream swirl flow; with the increase of momentum flux ratio,the downstream swirl flow will be destroyed gradually while the mainstream Reynolds number remains constant. Nevertheless,the mainstream Reynolds number has no evident effect on recirculation zone size or downstream swirl.)