Experimental thermal field measurements of film cooling above the suction surface of a turbine vane
Experimental thermal field measurements of film cooling above the suction surface of a turbine vane
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DOI：
10.1115/1.4030263
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发表时间：
2014-06
影响因子：
1.5
通讯作者：
W. R. Stewart;D. Bogard
中科院分区：
文献类型：
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作者：
W. R. Stewart;D. Bogard
通过实验测量了绝热和匹配的毕奥数模型涡轮机叶片上的单排薄膜冷却孔下游的二维热剖面。测量结果与相同模型和流动条件下的计算模拟结果进行了比较。以前，绝热和整体效率的比较已经在实验和计算数据之间进行。为了改进气膜冷却射流向下游传播时的演化计算模型，必须分析叶片上方的热场，而不仅仅是叶片表面上的足迹。本研究扩展了这些数据，包括二维温度场以上的叶片在0，5和10孔直径的气膜冷却孔下游。测试了四种吹气比，M = 0.28、0.65、1.11和2.41。在每种情况下，计算的射流都比实验射流冷，因为它们没有那么快地扩散到主流中。另外，在两种吹风比下的计算结果显示了气膜冷却中常见的肾形涡的影响，但实验温度场并不受该涡的支配。最后，通过比较绝热模型和匹配的毕奥数模型的结果，这些热场可以准确分析绝热壁温是否是传热驱动温度的合理估计值。版权所有© 2014 by ASME
Two-dimensional thermal profiles were experimentally measured downstream of a single row of film cooling holes on both an adiabatic and a matched Biot number model turbine vane. The measurements were taken as a comparison to computational simulations of the same model and flow conditions. Previously, adiabatic and overall effectiveness comparisons have been made between experimental and computational data. To improve computational models of the evolution of a film cooling jet as it propagates downstream, the thermal field above the vane, not just the footprint on the vane surface must be analyzed. This study expands these data to include 2-D thermal fields above the vane at 0, 5 and 10 hole diameters downstream of the film cooling holes. Four blowing ratios were tested, M = 0.28, 0.65, 1.11, and 2.41. In each case the computational jets remained colder than the experimental jets because they did not diffuse into the mainstream as quickly. In addition, the computational results for the higher two blowing ratios exhibited the effects of the kidney vortex commonly studied in film cooling, but the experimental thermal fields were not dominated by this vortex. Finally, in comparing results above adiabatic and matched Biot number models, these thermal fields allow for an accurate analysis of whether or not the adiabatic wall temperature was a reasonable estimate of the driving temperature for heat transfer.Copyright © 2014 by ASME