狭缝喷注-发散冷却的综合冷却效果数值研究 *

Numerical Investigation on Overall Cooling Effectiveness for a Combined Scheme of Slot Injection and Effusion Cooling

关键词:  狭缝喷注  发散冷却  组合冷却方式  综合冷却效果  数值模拟

Key words:  Slot injection  Effusion cooling  Combined cooling scheme  Overall cooling effectiveness  Numerical simulation

摘要:

为了研究发散孔阵列上游设置狭缝喷注的狭缝喷注-发散冷却组合方式的综合冷却效果，采用数值模拟方法对其冷却效果进行了研究，并在相同的冷却空气流量下与纯发散冷却方式进行了对比分析。结果表明:狭缝-发散孔组合冷却方式显著改善了发散孔阵列前区的冷却效果，平均冷却效果可以提升12%～16%；该组合冷却方式因狭缝喷注的分流而使得发散孔吹风比相对纯发散冷却有所减小，导致在小吹风比下发散孔下游区域的综合冷却效果低于单纯发散冷却结构，而在吹风比较大时，组合冷却方式与单纯发散冷却结构在发散孔阵列后区的综合冷却效果基本一致；随着狭缝高度的增加，发散孔阵列前区的综合冷却效果有所增强，而在发散孔阵列后区，综合冷却效果却略有下降。

Abstract:

Numerical simulation is carried out to study the overall cooling effectiveness for a combined scheme of slot injection and effusion cooling where the slot outlet is located upstream the effusion holes-array. The comparison between combined cooling scheme and pure effusion cooling scheme is made under the same coolant usage. The results show that the combined scheme of slot injection and effusion cooling improves significantly the overall cooling effectiveness in the front zone of effusion holes-array. There is an increase of 12%～16% in the averaged cooling effectiveness. This combined cooling scheme makes the blowing ratio of the effusion cooling part less than the correspondingly pure effusion cooling scheme due to the exist of slot injection， resulting in a little decrease of the overall cooling effectiveness in the rear zone of effusion holes-array in relative to pure effusion cooling under low blowing ratios. However， under high blowing ratios， the overall cooling effectiveness for a combined scheme is nearly the same as the pure effusion cooling scheme in the rear zone of effusion holes-array. As the increase of slot height， the overall cooling effectiveness is enhanced in the front zone while reduced a little in the rear zone of effusion holes-array.