为了探究吹风比、唇板厚度对叶片尾缘半劈缝冷却结构气膜冷却特性的影响，采用数值模拟方法对比唇板厚度为4，5和3 mm，吹风比Br为0.5，0.8，1.0和1.5条件下叶片尾缘后台阶上的气膜冷却效率。结果表明：在吹风比Br为0.5时，叶片尾缘后台阶上产生的回流区大，冷气向展向扩散范围广，冷气在近劈缝一端向展向覆盖的较好，由于吹风比小，冷气流速慢，动量小，在后台阶远端燃气与冷气掺混量大，导致冷气冷却能力降低；在大吹风比下（Br=1.5），冷气流速快，冷气从劈缝射出集中覆盖在劈缝下游处，而肋下游冷气覆盖效果差。唇板厚度影响着唇板出口处形成的回流区，增大唇板厚度将导致半劈缝出口气流分离所产生的涡强度变大，促进燃气与冷气的掺混，降低冷却效率，薄唇板会使尾缘气膜冷却效率显著提高。

In order to explore the influence of blowing ratio and lip thickness on the gas film cooling characteristics of the blade trailing edge semislit cooling structure,a numerical simulation method was used to compare gas film cooling efficiencies on the rear step of the blade trailing edge under the conditions of the lip thicknesses of 3mm,4 mm and 5 mm and the blowing ratios of 0.5,0.8,1.0 and 1.5.The results show that when the blowing ratio is 0.5,the backflow area generated on the rear step is large,the cold air diffuses widely in the spanwise direction,and the cold air covers well in the spanwise direction at the end near the split.Due to small blowing ratio,slow cold air flow rate and small momentum,the mixing amount of gas and cold air at the far end of the rear step is large,leading to the reduction of the cooling capacity of the cold air.At a large blowing ratio of 1.5,the cold air flow rate becomes faster,the cold air shot from the slits will be concentrated on the downstream of the slits,while the coverage effect of the cold air on the downstream of the ribs is poor.The thickness of the lip affects the recirculation zone formed at the outlet of the slice lip.Increasing the thickness of the slice lip will increase the strength of the vortex generated by the separation of the air flow at semislit outlet,promote the mixing of gas and cold air,and reduce the cooling efficiency.The thin lip will improve the cooling efficiency of gas film at the trailing edge significantly.

TK221

国家自然科学基金（52071107）；空气动力学国家重点实验室基金（SKLA-20190203）