A Research On The Methods For Calculating Performances And Stress Of Engine Cooling Fans

Engine cooling fan is an important component of engine cooling system. Its performances, which directly affect the cooling of engine, have important influence on the performances of engine. Now, engine cooling fan is asked for better performances and strength with the development of technology and the improvement of environmental awareness. Usually, design of fan is accomplished after times of trail producing, testing and minding. In order to change the method of design and reduce the time cost and economic cost, a method for analyzing the performances and stress of fan, based on CFD and fluid-structure interaction (FSI), is presented in this paper. The method is developed to provide guidance for fan design.As basic theories, the parameters and aerodynamics formulas of airfoil and cascade are presented. Then, the aerodynamic performance parameters of fan are presented in detail after the performance test system of fan and the test procedure is briefly introduced.Fan performances are analyzed by using CFD. As the base of modeling, the basic theories, computational methods and turbulence models of CFD are presented in this paper. Then, a single-blade model is established with Fluent to calculate the performances of fan. According to the comparison of the calculated results and experimental results, it is proved that CFD can predict the performances of fan and provide reliable reference to fan design.Fan stress is analyzed by using FSI. Basic theories of FSI, including classification of FSI problems, treatments of FSI problems and key questions of FSI are presented in the latter part of the paper. In order to analyze the stress of fan under influence of centrifugal force and air pressure, a FSI model is established with Adina. The stress distribution of calculated results demonstrates that FSI modeling can provide reliable reference to the strength design of fan.