학술논문
双肩壁凹槽叶顶冷却传热性能的优化研究 / A Study of Film Cooling and Heat Transfer Optimization for Double-Rim Squealer Tip
Document Type
Academic Journal
Source
西安交通大学学报 / Journal of Xi'an Jiaotong University. 58(1):68-80
Subject
Language
Chinese
ISSN
0253-987X
Abstract
为改善航空发动机透平第一级凹槽叶顶的冷却传热性能,利用自编程序搭建了凹槽叶顶的优化设计平台.采用三阶多项式响应面模型和 Hooke-Jeeves模式搜索算法的组合优化策略,获得了一种具有优良气热性能的透平级双肩臂凹槽叶顶结构,并将优化结果与传统凹槽叶顶、4 种典型双肩臂凹槽叶顶的传热和冷却性能进行了对比,分析了内肩臂的几何参数对凹槽叶顶流场结构和冷却传热性能的影响,评估了双肩臂凹槽叶顶冷却传热性能对设计变量的敏感性.结果表明:优化后的内肩臂分为上下两层;合理的内肩臂几何参数可有效降低泄漏流的冲击作用,有利于冷却流在内外凹槽区域形成良好的覆盖;与传统凹槽叶顶相比,优化后的双肩臂凹槽叶顶的平均传热系数下降了 24.96%,平均气膜冷却效率上升了 5.38%;叶顶平均传热系数对内肩臂下层的高度最为敏感,叶顶平均气膜冷却效率对内肩臂上层的起始位置更加敏感,而内肩臂上层的高度对双肩臂凹槽叶顶的冷却传热性能影响相对较小.
To improve the film cooling and heat transfer performance on the squealer tip of the first turbine stage in aero-engines,a design platform for optimization was constructed using a self-developed program,aiming at enhancing the film cooling effectiveness and minimizing heat transfer on the squealer tip.The Hooke-Jeeves searching algorithm combined with the third-order response surface model was utilized to find a proper double-rim squealer tip geometry with excel-lent aero-thermal performance.Additionally,a comparative analysis was conducted to assess the heat transfer and film cooling effects of the optimized double-rim squealer tip against those of the conventional squealer tip as well as four commonly used double-rim squealer tips.The study also investigated the influence of various geometrical parameters for inner-rim on the flow structures,heat transfer and film cooling effectiveness in the tip region,and involved evaluating the sensitivi-ties of heat transfer and film cooling performance on the double-rim squealer tip to various design variables.The findings indicated that the optimized configuration of the inner rim in the double-rim squealer tip consisted of two layers,an upper and a lower layer.The selection of appropriate geometrical parameters for the inner rim resulted in a reduction of the impingement effect caused by the leakage flow,providing effective coolant coverage on the internal and external squealer cavities.In comparison to the conventional squealer tip,the optimized double-rim squealer tip showcased a 24.96%reduction in the area-averaged heat transfer coefficient and a 5.38%en-hancement in the area-averaged film cooling effectiveness.The height of the lower layer in the in-ner rim had the most significant impact on the area-averaged heat transfer coefficient,while the starting location of the upper layer in the inner rim played a crucial role in the area-averaged film cooling effectiveness among the studied parameters.On the other hand,the height of the upper layer in the inner rim exhibited a relatively minor influence on the film cooling and heat transfer performance of the double-rim squealer tip.
To improve the film cooling and heat transfer performance on the squealer tip of the first turbine stage in aero-engines,a design platform for optimization was constructed using a self-developed program,aiming at enhancing the film cooling effectiveness and minimizing heat transfer on the squealer tip.The Hooke-Jeeves searching algorithm combined with the third-order response surface model was utilized to find a proper double-rim squealer tip geometry with excel-lent aero-thermal performance.Additionally,a comparative analysis was conducted to assess the heat transfer and film cooling effects of the optimized double-rim squealer tip against those of the conventional squealer tip as well as four commonly used double-rim squealer tips.The study also investigated the influence of various geometrical parameters for inner-rim on the flow structures,heat transfer and film cooling effectiveness in the tip region,and involved evaluating the sensitivi-ties of heat transfer and film cooling performance on the double-rim squealer tip to various design variables.The findings indicated that the optimized configuration of the inner rim in the double-rim squealer tip consisted of two layers,an upper and a lower layer.The selection of appropriate geometrical parameters for the inner rim resulted in a reduction of the impingement effect caused by the leakage flow,providing effective coolant coverage on the internal and external squealer cavities.In comparison to the conventional squealer tip,the optimized double-rim squealer tip showcased a 24.96%reduction in the area-averaged heat transfer coefficient and a 5.38%en-hancement in the area-averaged film cooling effectiveness.The height of the lower layer in the in-ner rim had the most significant impact on the area-averaged heat transfer coefficient,while the starting location of the upper layer in the inner rim played a crucial role in the area-averaged film cooling effectiveness among the studied parameters.On the other hand,the height of the upper layer in the inner rim exhibited a relatively minor influence on the film cooling and heat transfer performance of the double-rim squealer tip.