涡轮叶片前缘气膜冷却特性的研究

发布时间：2018-03-06 19:34

本文选题：涡轮叶片　切入点：前缘气膜冷却　出处：《南京航空航天大学》2016年硕士论文　论文类型：学位论文

【摘要】：提高涡轮前燃气温度可有效提高航空发动机推力和热效率。自20世纪60年代以来涡轮前燃气温度逐年增长,目前已远高于叶片材料耐热极限。叶片前缘区域直接承受高温燃气冲击,在整个涡轮中温度最高,常采用气膜冷却对此区域加以保护。本文通过实验和数值计算相结合的方法对叶片前缘气膜冷却特性开展研究,分析了气膜孔的孔型与孔位置对叶片表面换热特性的影响,为优化涡轮叶片冷却特性提供数据支撑。具体研究内容如下:(1)对叶片表面冷却效率和对流换热系数进行实验研究,分析了不同孔型和孔位置叶片的全表面冷却效率和对流换热系数规律。研究得出:在实验工况下,叶片的冷却效率和对流换热系数均随吹风比的增大而升高;冷却效率和对流换热系数在气膜孔出口区域最大,沿流向因气膜冷却效果减弱而降低,降至叶片尾缘区域达到最小值;若叶片前缘吸力面和压力面同时开有气膜孔,相同吹风比条件下,吸力面的冷却效率和对流换热系数皆比压力面的大;在气膜出流区域中,交叉孔叶片的冷却效率和对流换热系数均高于圆孔叶片。(2)运用Fluent软件对涡轮叶片的真实工况进行数值模拟来分析其气膜冷却特性,研究叶片前缘气膜孔对叶片冷却效率和对流换热系数的影响,并进行孔型与孔位置的对比。同时选取部分典型实验工况进行数值模拟对比,实验结果与数值模拟吻合较好。
[Abstract]:Increase the turbine inlet temperature can effectively improve the engine thrust and thermal efficiency. Since 1960s the turbine inlet gas temperature has increased year by year, far higher than the thermal limit. The blade material blade leading edge region directly under the impact of high temperature gas turbine, in the highest temperature, often with gas film cooling in this area should be protected. This method of combining through experimental and numerical studies on the cooling characteristics of leadingedge film, the effect of the pass analysis film holes and holes on the blade surface heat transfer characteristics, to provide data support for the optimization of turbine blade cooling. The specific contents are as follows: (1) on the blade surface cooling efficiency and convective heat transfer coefficient experimental study and analysis of the different type and hole position of leaf surface cooling efficiency and heat transfer coefficient law. The results show that under the experimental conditions, The blade cooling efficiency and the convective heat transfer coefficient decreased with the increase of blowing ratio increased; cooling efficiency and heat transfer coefficient at the outlet of film hole area, along the flow direction due to the film cooling effect decreased and decreased to the trailing edge reaches the minimum value; if the leading edge of the suction side and pressure side at the same time there the film hole, the same blowing ratio, the suction side of the cooling efficiency and the convective heat transfer coefficient are larger than the pressure surface; in the film flow region, cross hole vane cooling efficiency and heat transfer coefficient was higher than that of circular blade. (2) using Fluent software on the real working condition of turbine blade by numerical the simulation to analyze the film cooling characteristics, influence of blade leading edge film holes on the blade cooling efficiency and heat transfer coefficient, compared with the pass hole position. At the same time, select some typical experimental conditions for numerical simulation The experimental results are in good agreement with the numerical simulation.

【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V231.1

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