A Study On Optimization Of Engine Cooling Fan

As China’s economy continues to 30 years of development, we have now reached the stage of industrial transformation and upgrading. To improve the competitiveness, our products, especially in automobile industry, need to a lean design and lean manufacturing. As the cooling fan which is an important component of vehicle has a direct effect on performance of vehicle, it is significative to study optimization of cooling fan.Firstly, the research status of engine cooling fan is summarized in this thesis. Next, the performance parameter of cooling fan and the principle of testing device are described detailedly. What’s more, the theory of computing performance of cooling fan by Computational Fluid Dynamics(CFD) is introduced, and two cooling fans’ performance is calculated according to this theory. By comparison with the experimental results- error of less than 9%, the method of computing performance of cooling fan by CFD is proved to be practicable for optimization of cooling fan.Based on the theory of CFD, Design of Experiment(DOE), Approximation Models and Intelligent Optimization, a method which is applied to optimizing the structure of cooling fan in global is proposed in this thesis. The method is constructed on Isight which is commercial optimization software by integrating 4 commercial software-Matlab, Proe, Hypermesh and Fluent. A cooling fan is optimized by the method, and the result show that optimizing cooling fan in full factors-12 design variables does not have the practical value at current conditions. However optimizing cooling fan in 6 design variables which are selected by sensitivity analysis is available and the efficiency of the fan is improved by 2.15%.Finally, aiming at the inadequacy-black box operability and low efficiency of optimization- of the method mentioned in last passage, theories of Vortex Dynamics and Diagnosis Based on Local Dynamics which are applied to local dynamics optimization of cooling fan are used to optimize the design of cooling fan. The result of optimizing a cooling fan by this method shows that the harmful area of flow can be found by the method. Via promotion of the local structure of the fan at mentioned harmful area, the efficiency of the fan is improved by 2.2%~2.4% at the operating area.