风扇转子叶片前缘精细维修方案及流动特性分析

以某小型大涵道比涡扇发动机风扇转子作为研究目标，在前缘侵蚀对风扇转子气动特性衰退研究的基础上，开展叶片前缘维修方案的研究。鉴于当前采用人工打磨维修手段引起的前缘气动性能的不确定性，针对侵蚀叶片前缘进行精细参数化控制，利用遗传算法寻求几何约束下的前缘最佳维修优化方案。数值计算结果显示，通过前缘优化设计能够显著地提升前缘侵蚀叶片气动特性。相比于前缘侵蚀叶片，最佳维修方案叶片的等熵效率值在设计点和近喘点附近分别提高了1.21%和3.01%，基本恢复至原始叶片水平，展现出了优秀的气动特性。叶片前缘对于风扇转子叶片吸力面附面层发展影响明显，最佳前缘维修方案能够有效地降低近前缘边界层厚度，降低附面层内部的流动损失。

Fine maintenance of an eroded fan rotor and related flow characteristics analysis

Based on the decline analysis of aerodynamic characteristic with leading edge erosion, the fan rotor of a small type and high bypass ratio turbofan engine is employed to investigate the leading edge maintenance method. Since the manually polished method may bring uncertainty to the blade aerodynamic characteristics because of its various leading shapes, this paper aims at the eroded leading edge, makes comprehensive controlling of leading edge with detailed parameters, and utilizes genetic algorithm to identify the best leading edge maintenance plan under geometric constrains. Numerical results show that optimum maintenance method of eroded leading edge could improve the aerodynamic characteristics obviously. Compared with the eroded blade, the best maintenance plan could increase the isentropic efficiency of fan rotor with 1.21% and 3.01% at the designed point and near stall condition showing good aerodynamic characteristics and nearly making the aerodynamic performance of repaired fan blade back to the initial level. The leading edge can significantly affect the development of boundary layer of suction surface, and the best maintenance plan can effectively reduce the thickness of boundary layer thickness near the leading edge and decrease the flow loss of the boundary layer.