Practical application of large eddy simulation to film cooling flow analysis on gas turbine airfoils
Practical application of large eddy simulation to film cooling flow analysis on gas turbine airfoils
复制标题
大涡模拟在燃气轮机翼型气膜冷却流动分析中的实际应用
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
A. Tsuge
中科院分区：
文献类型：
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作者：
T. Takata;K. Takeishi;Y. Kawata;A. Tsuge
采用贴体坐标系下的大涡模拟方法对涡轮机叶片气膜冷却流场进行了数值模拟。利用平板表面单排孔的流场和绝热气膜冷却效率的实验测量值对湍流模型进行了调整。结果表明，主流边界层与喷射气膜冷却空气相互作用产生了肾形和马蹄形涡。将实验结果与本文分析的温度分布进行了比较。当x/d = 1时，无因次温度分布呈圆顶状，与实验结果定量吻合。大涡模拟还应用于求解涡轮机翼型的气膜冷却问题。如果用大涡模拟求解整个流场域，计算时间太长，求解不切实际。本文采用贴体坐标系下的大涡模拟方法，对涡轮机叶片附近的各向异性气膜冷却流场进行了数值模拟。叶栅流场采用{kappa}-{x2}模型求解，叶栅间距为一个气膜孔间距。通过使用这种混合数值方法，减少了CPU时间，并保证了数值精度。分析结果表明，通过气膜冷却孔吹出的气流与涡轮机翼型吸力面和压力面上的主流之间存在相互作用。研究还表明，气膜冷却气流的基本结构是由拱形内部二次流和马蹄涡控制的，其结构类似于通过平板上的冷却孔吹出的气膜冷却气流。在流场中，湍流结构对曲率（再层化）和流型的影响，包括主流和冷却射流之间的相互作用，被清楚地显示。根据温度场计算结果预测了叶片表面气膜冷却效率，并与试验结果进行了比较。«少
Large eddy simulation (LES) using body-fitted coordinates is applied to solve film cooling flow on turbine blades. The turbulent model was tuned using the experimental flow field and adiabatic film cooling effectiveness measurements for a single row of holes on a flat plate surface. The results show the interaction between the main stream boundary layer and injected film cooling air generates kidney and horseshoe shaped vortices. Comparison of the temperature distribution between experimental results and present analysis has been conducted. The non-dimensional temperature distribution at x/d = 1 is dome style and quantitatively agrees with experimental results. LES was also applied to solve film cooling on a turbine airfoil. If LES was applied to solve whole flow field domain large CPU time would make the solution impractical. LES, using body-fitted coordinates, is applied to solve the non-isotropic film cooling flow near the turbine blade. The cascade flow domain, with a pitch equal to one film cooling hole spacing, is solved using {kappa}-{epsilon} model. By using such a hybrid numerical method, CPU time is reduced and numerical accuracy is insured. The analytical results show the interaction between the flow blowing through film cooling holes and mainstream on the suction and pressuremore » surfaces of the turbine airfoil. They also show the fundamental structure of the film cooling air flow is governed by arch internal secondary flow and horseshoe vortices which have a similar structure to film cooling air flow blowing through a cooling hole on a flat plate. In the flow field, the effect of turbulent structure on curvature (relaminarization) and flow pattern, involving the interaction between main flow and the cooling jet, are clearly shown. Film cooling effectiveness on the blade surface is predicted from the results of the thermal field calculation and is compared with the test result.« less