冷气射流对壁式火焰稳定器流场特性及壁温分布影响数值研究

Numerical Study for Effects of Cooling Air Jet on Flow Characteristics and Temperature Distribution of Wall Flameholder

关键词:  加力燃烧室  火焰稳定器  数值模拟  流场特性  壁面温度

Key words:  Afterburner  Flameholder  Numerical simulation  Flow field characteristics  Wall temperature distribution

摘要:

为了满足先进加力燃烧室对于值班火焰稳定器工作可靠性的要求，设计了一种带气冷结构的壁式火焰稳定器，并采用数值模拟的方法研究了不同冷却孔角度对壁式火焰稳定器流场特性及壁温分布的影响。研究结果表明：设计的气冷壁式火焰稳定器可以有效抑制冷侧转角处的流动分离，避免热侧高温燃气通过冷却孔倒流进冷侧；通过调节稳定器斜板和后板上的开孔角度α和β，可以得到不同流场结构；当α>90°或β>90°时，凹腔内出现顺时针旋转的旋涡，主回流区变小；当α=30°和β=30°时，气冷结构对流场影响最小，随着α或β增加，流场变化越来越大；当α=90°和β=150°时，壁式稳定器的冷却效果最好。

Abstract:

To meet the requirements of advanced afterburner for the reliability of pilot flameholder， an air-cooled wall flameholder was designed， and numerical simulation method was employed to investigate the flow field characteristics and wall temperature distribution under different angles of cooling holes. Results show that the flow separation at the corner of air-cooled wall flameholder in bypass can be suppressed； hence， it could be prevented that the high-temperature gas flows back into the bypass through the cooling holes. Different flow field structures can be obtained by adjusting the angle of cooling holes α and β on the front and latter plate of flameholder. When α or β is greater than 90°， a clockwise rotating vortex appears in the cavity， and the main recirculation zone becomes smaller. At α=30° and β=30°， the flow field is slightly affected by the air-cooled structure， and it changes obviously as α or β increases. At α=90° and β=150°， the wall flameholder has a better cooling effect.