肋条结构对气膜冷却凹槽叶尖流动换热的影响

为有效抑制涡轮转子叶尖泄漏并改善叶尖热负荷，采用数值模拟的方法，对5种叶尖肋条结构的高压涡轮带气膜冷却突肩叶片流场进行计算，评估了不同叶尖肋条结构的气热性能。结果表明：在叶尖增加肋条结构能够有效调控叶尖空腔涡、刮擦涡、肋后涡和冷气肾形涡的路径，从而起到减小叶尖高表面传热系数区，提高叶尖平均气膜冷却效率的作用，同时有效降低了叶片压力侧前缘进入的泄漏流量，使得总压损失系数下降。凹槽尾缘压力侧半肋条结构具有最佳的气热性能，对泄漏流的阻碍作用最好，与无肋条情况相比，其叶尖平均表面传热系数降低了20.1%；平均气膜冷却效率提升了24.3%。

Effects of rib structure on flow and heat transfer characteristics of film cooling rotor blade with squealer tip

In order to inhibit the tip leakage flow and reduce the tip thermal load of turbine rotor blade, numerical simulation method was used to calculate the flow field of high pressure turbine rotor blade with film cooling of five structures of tip rib,and the aerothermal performance was evaluated.The results showed that the location and path of the cavity vortex, the scraping vortex, vortex induced by rib and the kidney eddies can be effectively controlled by adding rib structure, which can reduce the high surface heat transfer coefficient region and improve the average film cooling efficiency of the blade tip. At the same time, the tip leakage flowing into the leading edge of pressure side was reduced, and the total pressure loss coefficient caused by tip leakage flow was decreased. The aerothermal performance and the effect on adding leakage flow resistance of squealer tip with the half rib structure in the rear squealer cavity were the best. Compared with the case without ribs, the average surface heat transfer coefficient of blade tip was reduced by 20.1%, and the average film cooling efficiency was increased by 24.3%.