基于流热耦合的燃气轮机透平叶顶冷却设计

燃气轮机透平叶顶区域存在复杂的流动和换热问题，承受很高的热负荷。为了降低透平动叶叶顶温度，在透平叶顶现有结构的基础上提出气膜冷却和气膜+内冷通道冷却两种叶顶冷却方案，并通过流热耦合计算分析冷却升级前后叶顶区域的换热和流动特性。研究发现：叶顶气膜冷却方案可有效降低叶顶温度，特别是叶顶前缘至中弦区域；而气膜＋内冷通道冷却方案基于外部气膜冷却，结合内部冷却通道设计，可进一步降低叶顶尾缘的温度；与原型叶片相比，气膜+内部冷气通道的复合冷却设计可以使叶顶尾缘最高温度降低24 K。

Research on Cooling Design of Gas Turbine Blade Tip based on Conjugate Heat Transfer Method

Complex flow and heat transfer exist in the tip area of the turbine blades,the blade tip suffers extremely high thermal load.In order to reduce the turbine rotor blade tip temperature,two cooling schemes for blade tip of film cooling and film cooling plus inner cooling channel are proposed based on current turbine blade tip structure,the heat transfer and flow characteristics in this region are calculated and analyzed based on the conjugate heat transfer method before and after cooling update.The research shows that film cooling design can effectively reduce blade tip temperature,especially from leading edge to the mid chord region on the blade tip; and the cooling scheme of film cooling plus inner cooling channel based on the external film cooling is combined with the internal cooling channel design,which can furtherly reduce the temperature at blade tip trailing edge.The results show that the composite cooling design which combined film cooling with internal cooling channel can make the maximum temperature of the tip trailing edge be reduced by 24 K compared with the original model.