【作者】 刘利献；

【导师】 李少华；

【作者基本信息】 东北电力大学 ， 热能工程， 2007， 硕士

【摘要】 提高燃气轮机进口初温是提高燃气轮机效率的关键技术之一,相应地对叶片承受高温的要求越来越高,因此研究叶片气膜冷却的流动与传热特性对有效地保护叶片指导燃气轮机设计有着重要的意义。本文采用实验与数值模拟相结合的方法,研究了叶栅通道紊动射流的流动与传热特性。设计并搭建了低速直流风洞,利用IFA300热膜风速仪对单排射流孔射流的流场进行了测量,分析了单排射流孔射流的流动特性。采用标准k-ε紊流模型,基于SIMPLE算法,采用有限体积法对控制方程进行离散,对不同射流比M、不同入射角α、不同射流孔位置等工况的叶片气膜冷却进行了数值模拟,分析总结了这些因素对射流温度场的影响。结果表明,在吸力面尾部流场中形成了尾迹区,射流使得尾迹区较靠近射流孔,尾迹区变厚,尾迹涡变大。在射流比0.6～4.0之间,射流比为2.0时冷却效果最好;在45°、60°、90°三种入射角之间,90°入射角时冷却效率最低,45°入射角时与60°入射角时的冷却效率相比,先减小后增大;比较3.0D、4.5D两种孔间距,孔间距为3.0D时可以使两射流孔中心面沿主流方向之间的吸力面上形成较好的冷气膜;相同条件下比较不同的射流孔位置对冷却效率的影响,距离叶片前缘最近的射流孔的冷却效率最低。更多还原

【Abstract】 Enhancing the temperature of gas turbine’s inlet is one of the key technology to improve the efficiency of the gas turbine, and the requirement the blade bearing the high temperature is much higher than before. As a result, investigating on flow and heat transfer performance of blade’s film cooling possesses is important to protect the blade effectively and design the gas turbine.The paper adopted the experimental and numerical simulation method to study the blade cascade’s flow and heat transfer performance of turbulent jet. A large wind tunnel of low speed wind is designed and built. IFA300 hot film anemometer is applied to measure the flowing field of the single row jet hole and analyze its flow performance. Basing on SIMPLE algorithm and discretizing the control equation in finite volume method, standard k-εturbulence model is applied, to numerical simulate film cooling in different jet rate, different angle of incidence and different jet hole position. The effective factors to jet hole’s temperature is also analyzed.The results shows that the foot section of suction surface flow field format wake region. The jet makes the wake region close to jet hole and the wake region become thickener and the wake vortex become bigger. Between 0.4~0.6, when jet rate equal to 2.0 the cooling efficiency is best; among 45 degree, 60 degree and 90 degree angle of incidence, the 90 degree’s cooling efficiency is minimum. Comparing the 45 degree and 60 degree’s angle of incidence the cooling efficiency, the former elevated earlier and decline afterward; Comparing the 3D and 4.5D hole distance, when hole distance is 3D,the suction surface between the centre plane along the mainstream a preferable cold film is formatted. Comparing the different hole position effective to the cooling efficiency in same condition, the most closely to the anterior border of blade hole’s efficiency is worst.更多还原