气膜孔分布对凹槽叶顶传热和冷却性能的影响

发布时间：2018-01-09 15:07

本文关键词：气膜孔分布对凹槽叶顶传热和冷却性能的影响　出处：《西安交通大学学报》2016年05期 　论文类型：期刊论文

【摘要】：采用数值求解RANS方程的方法研究了典型燃气透平动叶凹槽叶顶的传热和气膜冷却性能,通过计算获得了3种叶顶间隙(1.31mm、1.97mm和3.29mm)、2种吹风比(1和2)、2种气膜孔分布(中弧线位置单排孔、中弧线+近压力面位置两排孔)条件下叶顶传热系数和气膜冷却有效度分布,并与实验结果进行了对比。结果表明:对于中弧线位置的单排气膜孔,冷却流可以对凹槽底部近压力面侧形成有效的冷却;随着吹风比的增大,凹槽底部靠近前缘吸力面侧的高传热系数区域减小,凹槽底部压力面侧的传热系数减小且气膜冷却有效度显著增大;随着叶顶间隙的增大,凹槽底部前缘吸力面侧的高传热系数区向压力面侧扩大,凹槽底部平均传热系数明显增大,凹槽底部近压力面侧和尾缘处的气膜冷却有效度减小。对于中弧线+近压力面两排气膜孔,近压力面气膜孔内的冷却流覆盖了凹槽肩壁和叶顶尾缘区域,且强化了凹槽底部靠近压力面侧的冷却性能;随着吹风比的增大,凹槽底部近压力面侧、肩壁和叶顶尾缘区域的传热系数明显减小,气膜冷却有效度明显增大;随着叶顶间隙的增大,凹槽底部吸力面侧高传热系数区域向压力面侧扩大,凹槽底部近压力面侧、肩壁和叶顶尾缘区域的传热系数显著增大,气膜冷却有效度减小。
[Abstract]:The heat transfer and film cooling properties of the top of the groove blade of a typical gas turbine blade are studied by solving the RANS equation numerically. The results show that the clearance of three kinds of blades is 1.31mm. 1.97mm and 3.29mm respectively. Two kinds of air blowing ratio (1 and 2) and 2 kinds of film pore distribution (one row hole in the middle arc line). The heat transfer coefficient and the effective distribution of film cooling are compared with the experimental results under the condition of two holes near the pressure surface of the middle arc. The results show that: for the single exhaust film hole in the middle arc position. The cooling flow can effectively cool the bottom of the groove near the pressure side; With the increase of blowing ratio, the region of high heat transfer coefficient near the front suction surface at the bottom of the groove decreases, the heat transfer coefficient on the pressure side of the bottom of the groove decreases and the effective degree of film cooling increases significantly. With the increase of blade tip clearance, the high heat transfer coefficient area of the suction side of the front edge of the groove bottom expands to the pressure side, and the average heat transfer coefficient at the bottom of the groove increases obviously. The effectiveness of film cooling at the bottom of the groove near the pressure side and the tail edge is reduced. For the two film holes in the middle arc near the pressure surface, the cooling flow in the film hole near the pressure surface covers the recessed shoulder wall and the tip and tail edge of the blade. The cooling performance of the bottom of the groove near the side of the pressure surface is enhanced. With the increase of the blowing ratio, the heat transfer coefficient of the shoulder wall and the tip and tail edge of the blade decreases obviously, and the effective degree of film cooling increases obviously at the bottom of the groove near the pressure side. With the increase of blade tip clearance, the region of high heat transfer coefficient of suction surface at the bottom of groove expands to the side of pressure plane, and the heat transfer coefficient of bottom of groove near pressure plane, shoulder wall and tip and tail edge of blade increases significantly. The effectiveness of film cooling is reduced.
【作者单位】：西安交通大学能源与动力工程学院;
【基金】：国家自然科学基金资助项目(51306138)
【分类号】：TK14
【正文快照】： 燃气透平第一级动叶工作在高温、高压、高转速的环境中,叶顶区域承受着较高的热负荷和热应力。叶顶间隙内流场结构复杂,所以叶顶区域的流动、传热和冷却性能一直是制约叶片气动性能、影响安全运行的关键因素。目前,对燃气透平叶顶传热、冷却性能的研究主要有实验测量和数值模

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