中文摘要：

发动机是汽车的动力源，而冷却风扇是发动机正常工作的重要保证。基于计算流体力学分析方法，对影响冷却风扇性能的结构参数进行分析，对冷却风扇进行优化设计。建立不同轮毂比、叶片数等的三维模型，利用计算流体力学软件FLUENT对模型进行流场分析，选取入口静压、空气流量、有效功率等参数的变化规律进行对比分析，并采用正交分析法分析二者综合作用下冷却风扇结构参数的最优值。选取优化后冷却风扇轮毂比为0．45、风扇叶片10片，采用风洞试验和发动机台架试验对比优化前后冷却风扇性能变化，并对仿真分析的准确性进行验证。结果可知，优化设计后冷却性能变化明显，仿真与试验误差在5％以内，研究方法和结论可以作为设计生产的参考依据。

英文摘要：

The engine is the power source of the car, and the cooling fan is an important guarantee for the normal operation of the engine. Based on computational fluid dynamics method （CFD）, structural parameters that affect the performance of the cooling fan are analyzed to optimize the design of cooling fa- The three-dimensional model of different hub ratio and the number of leaves are established. It use computational fluid dynamics software FLUENT to analyze the flow field. Comparative analysis of the variation of the inlet static pressure, airflow rate, effective power and other parameters is done. The optimal values of cooling fan structure parameters are analyzed by orthogonal analysis method in two. Chooses the best performance cooling fan with hub ratio of 0.45 and fan blades lO films, and uses the cooling fan wind tunnel test and engine test contrast the performartce before and after the optimal design, and to verify the accuracy of the analysis. The result shows that the optimized design of the cooling performance changes signifwantly, simulation and experimental error is less than 5 percent, research methods and conclusions can be used in production design.