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为了研究全气膜冷却涡轮导叶叶片的换热特性,采用瞬态液晶技术获得了叶片全表面的高分辨率换热系数和冷却效率.实验在三叶片两通道放大模型中完成,叶栅进口雷诺数是1.0×105.叶片前缘有8排复合角孔,压力面有21排轴向角孔,吸力面有24排轴向角孔.气膜孔排由2个供气腔供气,前腔二次流与主流的质量流量比为4.56%,后腔为4.67%.结果表明:受叶栅通道涡作用,气膜出流在吸力面呈聚敛状,在压力面则呈发散状.气膜出流受气膜孔角度影响,气膜孔下游的换热系数和冷却效率都较高.叶片前缘受到冲击,换热强,冷却效率低;叶片吸力面冷却效率维持在0.4左右,压力面维持在0.35左右.该全气膜冷却叶片气膜覆盖效果较好,冷却效率和换热系数分布均匀,是一种较好的冷却结构.
In order to study the heat transfer characteristics of all-film-cooled turbine guide vane, transient liquid crystal technology was used to obtain the high-resolution heat transfer coefficient and cooling efficiency of the entire surface of the blade.The experiment was completed in a three-blade two-channel amplification model, The Reynolds number is 1.0 × 105. The leading edge of the blade has 8 rows of composite angular holes, the pressure surface has 21 rows of axial angular holes, and the suction surface has 24 rows of axial angular holes.The film hole row is supplied by two air supply cavities, The mass flow ratio of the secondary cavity to the mainstream was 4.56% in the front cavity and 4.67% in the back cavity. The results showed that the outflow of the film was convergent on the suction surface and divergent on the pressure surface. The outflow of the gas film is affected by the angle of the gas film hole, and the heat transfer coefficient and cooling efficiency of the downstream of the gas film hole are high, the leading edge of the film is impacted, the heat exchange is strong, and the cooling efficiency is low; the cooling efficiency of the suction surface of the blade is maintained at about 0.4, Surface maintained at about 0.35. The film coverage of the full film cooling blade is better, the cooling efficiency and heat transfer coefficient are evenly distributed, is a good cooling structure.