发动机冷却风扇是车辆冷却系统的重要组成部分，静压和轴功率是评价其气动 性能的重要指标，而叶尖作为风扇做功的主要部分对风扇气动性能有较大影响． 以发动机 冷却风扇为研究对象，研究了风扇气动性能的计算方法和叶尖参数的优化方法． 首先给出 了风扇气动性能的计算方法，依据试验台建立风扇计算模型，利用模型仿真得到风扇在某 一转速下的性能曲线，并与试验值进行了对比验证;然后以叶尖安装角、叶尖弦长、叶尖拱 高为变量设计新风扇，基于正交试验法对各叶尖参数进行优化组合，给出了风扇叶尖参数 的优化方法;最后通过风扇性能曲线、叶片压力图、叶片速度矢量图对优化结果进行分析， 验证了优化方法的可行性． 文中关于风扇叶尖参数的分析与优化方法，对发动机冷却风扇 的设计具有指导意义．

The engine cooling fan is an important part of the vehicle cooling system． Static pressure and shaft po- wer are important indicators to evaluate its aerodynamic performance，and the tip of the blade as a main part of the fan work has a great influence on the aerodynamic performance of the fan． Taking the cooling fan of the engine as the research object，the calculation method of aerodynamic performance of the fan and the optimization method of blade tip parameters were studied． Firstly，the calculation method of fan aerodynamic performance was given，and the fan calculation model was established according to the test bench． Then a new fan was designed with the tip mounting angle，the tip length and the tip arch height as the variables． Based on the orthogonal test method，the parameters of the blade tip parameters were optimized and combined，and the optimization method of the fan tip pa- rameters was given． Finally，the optimization results were further analyzed from fan performance curve，blade pressure diagram and blade velocity vector diagram，and the feasibility of the optimization method was verified． This analysis and optimization method of fan tip parameters is of guiding significance for the design of engine cooling fan．