关键词: 涡轮动叶, 凹槽状叶顶, 气膜冷却, 不确定性量化, 敏感性分析

Abstract:

This study proposes an efficient gas turbine blade aerothermal performance uncertainty system based on the genetic algorithm acceleration strategy， and develops a method for uncertainty data analysis of the blade tip aerothermal properties. The proposed system and method are utilized for the quantitative study of the uncertainty in the aerothermal performance of a squealer tip with film cooling structure， taking into account the operating condition fluctuation and geometrical parameter deviation. The results show that coolant jet injection will enhance the unsteady tendency of the downstream flow field of the first-stage rotor blades. In the actual operation of the gas turbine， the film cooling effectiveness in the region predicted at the design stage to be adequately covered by the coolant jet will be much lower than the value obtained from the deterministic calculations. Under the impact of the uncertainty inputs， the film cooling effectiveness of the squealer tip meets the Normal distribution. The mean value is reduced by 20.06% compared with the design value， and the probability of 10% deviation from the design value is as high as 81.84%. The result of sensitivity analysis shows that the main parameter affecting the fluctuation of the total downstream pressure loss coefficient is the tip clearance deviation， with the variance index as high as 87.21%. The total inlet temperature fluctuation is the key parameter affecting the uncertainty of the film cooling effectiveness， with the variance index of 84.01%.

Key words: turbine blade, squealer tip, film cooling, uncertainty quantification, sensitivity analysis