Performance Simulation And Fin Optimization Design Of Louvered Fin Radiator

As the key component in the automobile cooling system,louvered fin radiator plays an important role in maintaining stable operation of vehicle.In recent years,with the development of powerful engines,as well as the use of heating elements such as power batteries,motors and motor controllers in the electric vehicles,the heat need to be removed by cooling system increases.Meanwhile,the trend of vehicle energy-saving and emission-reduction puts forward light and compact design requirements for louvered fin radiator.Therefore,the key to optimize the performance of the louvered fin radiator is to realize the lightweight design and improve comprehensive heat transfer performance of the radiator.Based on the theoretical basis of computational fluid mechanics and heat transfer,this paper took a louvered fin radiator provided by a cooperative company as the research object.Without changing the characteristics of cool-water side,this paper carried out an in-depth research on the structure parameters,layout and structure forms of the louver fin,including its influence on heat transfer and flow performance and its optimized design.The heat transfer model of the louver fin and the louvered fin radiator were established.The software FLUENT was used to simulate the fluid-thermal-structural coupling to obtain the heat transfer and flow performance at different fluid velocity conditions.The simulation results of air side temperature rise,air side pressure drop,cool-water side temperature difference and cool-water side pressure drop of the louvered fin radiator were simulated.And the accuracy of the model simplification and numerical simulation method was verified.By comparing the results between simulation data of original model and test data of wind tunnel,the accuracy both of model reduction method and simulation method were indicated.With the structure parameters of the louver fin as test factor,the heat transfer factor j,the friction factor f and the weight evaluation index m/F_p as evaluation indexes,an orthogonal test was arranged to explore the influence trend of structural parameters on fins weight and performance.And with the help of the Box-Behnken test,the optimum structure parameters of the louver fin were obtained by the response surface optimization design method,which actualized the lightweight design.The results showed that its unit weight decreased by 15.5%compared with that before optimization.In order to further improve the heat exchange and flow performance,a new type of louver fin structure was proposed in this paper,which was designed to be a cone shaped structure with variable thickness.The influence of cusp conical section thickness and louver spacing decrement on fin performance was analyzed in sequence.The results showed that the overall heat transfer performance of the fin is the best when the thickness of the middle section is 0.2mm and the spacing decrement of the louvers is 0.06mm.After selecting the optimization scheme,the comprehensive performance evaluation factor JF was 9.1%higher than the fin lightweight model,which effectively improved the comprehensive heat transfer capability of fins.The light weight design of louvered fins and the optimization method of comprehensive heat transfer performance involved in this paper can provide theoretical guidance for the design and development of the air side structure of the same type louvered fin radiator.