水平喷流对叶顶气膜冷却效率影响的数值研究

发布时间：2018-06-25 18:45

本文选题：气膜冷却 + 叶片　；参考：《航空动力学报》2016年04期

【摘要】：为进一步提高燃气轮机叶顶区域的气膜冷却效率,在叶顶模型结构上对4种叶顶冷却结构的流动和传热进行了数值模拟,结果显示带有盖板的水平喷流结构能够有效地提高叶顶区域的气膜冷却效率,对于圆孔,可以将气膜冷却效率提高至原来的2倍以上.通过流场的分析发现:水平喷流结构可以调整冷却工质的流动,使得冷却工质的贴壁性更好、分布更加均匀,进而提高气膜冷却效率.此外还研究了间隙宽度、盖板尾缘厚度、盖度和整流栅对水平喷流结构气膜冷却效率的影响.结果表明:增加盖度和减小间隙宽度可以提高气膜冷却效率,但是盖度和间隙宽度的选取受到了强度、工艺和冷却工质入口压力等因素的限制.水平盖板结构的冷却效果比倾斜盖板结构的好.整流栅足够长时可以调整流动、提高气膜冷却效率.
[Abstract]:In order to further improve the film cooling efficiency in the blade top region of gas turbine, the flow and heat transfer of four kinds of blade top cooling structures were numerically simulated on the blade top model structure. The results show that the horizontal jet structure with cover plate can effectively improve the film cooling efficiency in the tip of the blade, and for the circular hole, the film cooling efficiency can be increased to more than 2 times of the original one. Through the analysis of the flow field, it is found that the horizontal jet structure can adjust the flow of the coolant, which makes the cooling fluid more adherent to the wall and more evenly distributed, thus improving the cooling efficiency of the film. In addition, the effects of gap width, thickness of the trailing edge of the cover plate, cover degree and rectifier gate on the film cooling efficiency of the horizontal jet structure are also studied. The results show that increasing coverage and decreasing gap width can improve film cooling efficiency, but the selection of coverage and clearance width is limited by such factors as strength, process and inlet pressure of coolant. The cooling effect of horizontal cover plate structure is better than that of inclined cover plate structure. When the rectifier gate is long enough, the flow can be adjusted to improve the film cooling efficiency.
【作者单位】：武汉大学动力与机械学院;
【分类号】：TK471

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