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采用数值模拟的方法,研究了主流跨声速条件下,高压涡轮中平面叶尖上气膜冷却的流动和传热特性.在不带冷却的平面叶尖上,激波在端壁和叶尖表面来回反射,从叶片中部到尾缘,叶尖表面传热系数呈现条带状分布.采用气膜冷却方法后,冷却气体使得叶尖间隙内的流体减速,激波和叶尖上表面传热系数分布的条带结构不明显.冷却气体覆盖了冷却孔下游的区域,当冷却孔进口和叶栅进口总压比从0.7增大到1.0时,叶尖平均气膜冷却效率从18.7%下降到11.5%.和不采用气膜冷却的平面叶尖相比,当气膜孔进口和叶栅进口总压比为0.9时,叶尖平均表面传热系数增加了16.9%,传热量降低了8.7%.
The numerical simulation method was used to study the flow and heat transfer characteristics of the film cooling on the plane tip of the high-pressure turbine under the condition of the main transonic sound velocity. On the plane tip without cooling, Back and forth from the blade center to the trailing edge, the tip surface heat transfer coefficient showed a strip-like distribution.Using the film cooling method, the cooling gas makes the tip clearance of the fluid slowdown, the shock wave and tip surface heat transfer coefficient The distribution of the strip structure is not obvious.Cooling gas covers the area downstream of the cooling hole, when the cooling hole inlet and the total inlet pressure ratio increased from 0.7 to 1.0, the average tip film cooling efficiency decreased from 18.7% to 11.5 %. The average surface heat transfer coefficient increased by 16.9% and the heat transfer decreased by 8.7% when the total inlet pressure ratio between the film hole inlet and the cascade inlet was 0.9, compared with the flat blade without the film cooling.