一体化加力燃烧室冷态流动特性数值研究

将混合扩压器与火焰稳定器融为一体设计，并引入外涵冷流对高温结构件进行强化冷却，采用数值仿真方法，对比分析入口涵道比（0.278~0.583）和总温比（0.418~0.464）对一体化加力燃烧室中流动特征及其冷却性能的影响。结果表明:在研究参数范围内，大部分外涵冷流冷却隔热屏或直接进入加力燃烧室参与混合，仅有少部分进入火焰稳定器和联焰器，对其下游回流区没有影响，便于组织燃烧与稳定并传播火焰；外涵气流的流量分配对涵道比和温比变化不敏感；涵道比增加，特征面的流量系数下降约6.2%，总压恢复系数下降约3.2%，但是沿程热混合效率增加约6.1%；火焰稳定器的冷却效率随涵道比增加而提升约37.2%，但是其表面峰值温度降低不明显；温比对于该结构的流动特征与冷却特性影响都很小。 

Numerical study on cold flow characteristics of integrated afterburner

The diffuser and flame holder were integrated into design, and the bypass cold flow was introduced to cool high temperature structures in the integrated afterburner. Numerical simulation was conducted to analyse the effects of the bypass ratio (0.278-0.583) and total temperature ratio (0.418-0.464) on the flow characteristics and cooling performance of the integrated afterburner. The results indicated that within the range of parameter, most of the bypass flow cooled the liner or directly entered the afterburner to participate in mixing with primary flow. A small amount of the bypass flow which had no effect on the recirculation zone located on the downstream flame holder entered the flame holder and interconnector. So, it was convenient for organizing the combustion, stabilizing and propagating the flame. The distribution of bypass flow was insensitive to the change of bypass ratios and temperature ratios. With the increase of bypass ratio, the flow coefficient of specific faces decreased by 6.2%, and the total pressure recovery coefficient decreased by 3.2%, but the thermal mixing efficiency along afterburner increased by 6.1%. The average cooling effectiveness of the flame holder increased by about 37.2% with the increase of bypass ratio, but the peak temperature did not decrease significantly. The temperature ratio had very little effect on the flow characteristics and cooling performances of the integrated afterburner.