几何结构对尾缘层板气膜冷却特性的影响

Investigation on the effects of geometrical structure on film cooling performance of trailing edge lamilloy

将层板冷却结构用于叶片尾缘叶盆侧,通过数值模拟改变冲击孔和扰流柱的排布,唇板厚度以及缝宽,研究其对劈缝气膜冷却的影响。结果表明,冲击孔和扰流柱位置的改变,对外部劈缝下游气膜冷却基本无影响;唇板厚度的改变对冷却效率和换热系数分布均有一定影响,唇板厚度减小,劈缝下游冷却效率降低,换热系数增大,相对于原始结构,唇板的改变使得劈缝下游气膜展向平均冷却效率提高65.0%;缝宽的改变对冷却效率和换热系数分布均有较大影响,缝宽越大,冷却效率越高,劈缝下游换热系数减小,劈缝间下游换热系数增大,相对于其他几种结构,缝宽增加劈缝下游的冷却效果最好,展向平均冷却效率最多提高116.5%。

Lamilloy models are applied to blade trailing edge. Numerical simulations are used to change the location of impinge- ment holes and pin fins, the thickness of lip and the width of slot to study changes to study the effect of these changes on the vane＇s trailing edge outer film cooling performance. The results show that different location of impingement holes and pin fins have little im- pact on the vane＇s trailing edge outer film cooling performance. Different thicknesses of lip have an influence on film cooling effectiveness and heat transfer coefficient; The film cooling effectiveness of slots becomes smaller with the decrease of lip＇s thickness and film cooling effectiveness between slots becomes larger with the decrease of hp＇s thickness, and the heat transfer coefficient becomes larger with the decrease of lip＇s thickness. Compared to the original structure, the maximum increase of the spanwise averaged film cooling effectiveness is 65.0% with the changing of the lip＇s thickness. Different widths of slot have a great influence on film cooling effectiveness and heat transfer coefficient, the film cooling effectiveness becomes larger with the increase of slot＇s width. The heat transfer coefficient of slots becomes smaller with the increase of slot＇s width and the heat transfer coefficient between slots becomes larger with the increase of slot＇s width. The best film cooling performance can be achieved by increasing slot＇s width, the maximum increase of the spanwise averaged film cooling effectiveness is 116.5%.