机匣附面层对涡轮转子叶顶流动及换热的影响

以GE-E3型燃气涡轮发动机第1级高压涡轮转子为对象,通过改变进口段长度、机匣的壁面条件以及叶顶间隙的高度,调节二次流与泄漏流之间的强弱关系,分析了机匣附面层对叶顶区域气流流动和叶顶壁面换热特性的影响,并研究了叶顶边缘的倒圆处理对叶顶气流流动和壁面换热的影响.结果表明:泄漏流与二次流的相互作用,导致叶顶头部吸力面侧产生了高换热系数区域;减少二次流或增加泄漏流,均可使得叶顶头部吸力面侧的高换热系数区域减小,压力面侧的高换热系数区域增大.

Effects of Turbine Casing Boundary Layer on the Flow Field and Heat Transfer at Tip Region of Turbine Blade

At the tip of the turbine blade, there are leakage flow and secondary flow, the interaction between which has significant influences on the flow and heat transfer of tip region. While casing boundary layer is the main source of secondary flow, the length of import segment, the wall conditions of casing and tip clearance height are changed to adjust the strength of leakage flow and secondary flow in order to analyze the effects of casing boundary layer on blade tip region flows, particularly tip wall heat transfer. Calculations have been performed on the GE-E3 first stage high pressure turbine rotor and the result shows that the interaction between leakage flow and secondary flow has noticeable effects on the tip heat transfer of the suction surface side, and both reducing secondary flow and increasing leakage flow can decrease the tip heat transfer on the suction surface side but enhance the tip heat transfer on the pressure surface side. In addition, the influence of the radiused edge blade on the tip leakage flow and heat transfer has been discussed in order to provide a reference for the analysis of the tip flow and heat transfer in the multi level and complex casing conditions.