【作者】 胡晓东；

【导师】 常海萍；

【作者基本信息】 南京航空航天大学 ， 工程热物理， 2010， 硕士

【摘要】 冲击+气膜复合冷却是现代航空发动机涡轮叶片所采用的典型冷却方式。本文以航空发动机涡轮叶片内部的冷却结构为研究背景,开展阵列冲击射流+溢流冷却结构流动换热特性的数值和实验研究,为精确设计高性能的涡轮叶片提供理论依据和技术支持。首先,本文对平板阵列冲击射流+溢流冷却结构流动换热特性进行了数值模拟和实验研究,针对不同冲击孔与气膜孔相对位置,气膜孔的倾斜角度等结构参数和不同射流雷诺数、初始横流与射流密流比以及气膜出流与初始横流密流比等流动参数对流动换热特性的影响规律进行了分析,发现:(1)不同的相对位置对流动特性的影响不大,而对换热略有影响,冲击孔位于气膜孔的正后方时的换热稍好;(2)气膜斜孔的换热优于气膜直孔,流动损失也更大;(3)射流雷诺数是决定换热的最主要因素,射流的增加使换热效果显著增强,流阻增大;(4)初始横流的引入有利于换热;(5)气膜出流越多,溢流作用越明显,换热越好;(6)实验结果与计算结果规律完全一致。然后,本文又对凹面阵列冲击射流+溢流冷却结构流动换热特性进行了数值模拟和实验研究,主要探讨了射流雷诺数和气膜出流与射流密流比等流动参数的变化对流动换热特性的影响规律,得到以下结论:(1)随射流雷诺数的增大,换热显著增强,总压损失系数增大;(2)随气膜出流量的增多,换热略有增强,但是总压损失系数变化不大;(3)实验结果与计算结果规律完全一致。更多还原

【Abstract】 Composite cooling (impingement / filming ) of turbine blade is a typical cooling method. Based on internal cooling structures of turbine blade, numerical and experimental study are conducted to reveal flow and heat transfer characteristics of array impingement jet /outflow, inorder to provide theoretical basis and technical support for precise design of high-performance turbine blades.First, as for panel array impingement jet /over flow, the following conclusions are obtained: 1.different relative positions have little impact on flow characteristics, but a slight change over heat transfer ; heat transfer performance is slightly better when impingement hole located backside film hole; 2.film inclined hole has better heat transfer performance than upright hole with larger flow loss; 3. jet Reynolds number is the most important factor of heat transfer performance, the increment of jet contributes to significant enhancement of heat transfer effectiveness but with larger flow loss; 4.initial crossflow does good to heat transfer performance; 5. The more film outflow, the stronger the outflow effectiveness, the better hear transfer; 6. the experiment results are fully consistent with the calculation results.Afterwards, this paper put a study on concave plate array impingement jet /outflow and concludes several conclusions: 1. As the jet Reynolds number increases, heat transfer performance enhances greatly while total pressure loss coefficient increases too; 2. Increment of film outflow has slight impact on heat transfer and little contribution to total pressure loss coefficient; 3. the experiment results are fully consistent with the calculation results.更多还原