Influence of internal parallel and v-shaped ribs on the discharge coefficient of a cylindrical film cooling hole
Influence of internal parallel and v-shaped ribs on the discharge coefficient of a cylindrical film cooling hole
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内部平行V形肋对圆柱形气膜冷却孔流量系数的影响
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
H. Bauer
中科院分区：
文献类型：
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作者：
C. Heneka;A. Schulz;H. Bauer
本文对燃气涡轮机叶片内冷通道内的气膜孔的排气特性进行了实验研究，主要研究了肋片布置方式和横流速度对排气特性的影响。两个矩形截面的直流道模拟了气膜冷却孔进出口处的横流情况。这两个通道由一个直径为10 mm、倾角为30°、长径比为6的单个按比例放大的气膜冷却孔连接。在不同的内部横流马赫数和肋几何形状下，对平行和垂直方向的内部和外部横流进行了测量。在冷却通道的一个壁处的孔的入口的上游和下游布置了具有方形横截面和相对于内部横流方向的四个不同角度（45°、60°、75°和90°）的平行和V形肋。肋的高度等于孔的直径，肋的节距与高度之比为10。内部横流马赫数在0和0.37之间变化。数据表明，在冷却剂通道的壁上放置肋可能导致流量系数减小、不变甚至增加。内部横流马赫数和冷却剂通道相对于孔轴的方向已被确定为主要影响参数。
An experimental study has been conducted to investigate the discharge behaviour of cylindrical film cooling holes with the main focus on the effects of rib arrangement and crossflow velocity inside the internal cooling passage of a gas turbine blade. Two straight flow channels of rectangular cross-section simulate the crossflow situations present at the inlet and outlet of a filmcooling hole. The two channels are connected by a single scaled-up film cooling hole with adiameter of 10 mm, an inclination angle of 30°, and a length-to-diameter ratio of 6. Measurements have been performed at various internal crossflow Mach numbers and rib geometries for both parallel and perpendicular orientations of internal and external crossflows. Parallel and v-shaped ribs with quadratic cross-section and four different angles with respect to the internal crossflow direction (45°, 60°, 75°, and 90°) have been placed upstream and downstream of the entrance of the hole at one wall of the cooling passage. The rib height equals the hole diameter, the rib pitch to height ratio is 10. The internal crossflow Mach number has been varied between 0 and 0.37. The data show that placing ribs onto the wall of the coolant passage may result in reduced, unchanged, or even increased discharge coefficients. Internal crossflow Mach number and orientation of the coolant passage in respect to the hole axis have been identified as major influencing parameters.