Study On Influence And Optimization Of Cooling Modules Layout On Heat Dissipation Performance Of Underhood

Automobiles play an increasing important role in national lives.With the continuous improvement of the overall performance of vehicles and the increasingly compact layout of engine compartment,the heat load of vehicles is also increasing,and the problems of heat dissipation of underhood have become prominent extraordinarily.The heat dissipation performance of the underhood directly affects the reliability and economy of the whole vehicle.However,the layout of cooling modules has a direct influence on the radiating performance of the underhood.In this article,the flow field and temperature field of engine compartment are analyzed by using the method combined the computational fluid dynamics(CFD)numerical simulation with experimental verification.In particular,the heat dissipation performance of engine cabin is optimized from the angle of the cooling modules layout.The main research contents and results of this dissertation are as follows:(1)The numerical model of underhood was established.? The appropriate turbulence model,discrete scheme,discrete method and flow field calculation algorithm were selected to make theoretical preparation for the analysis of flow field and temperature field of underhood.?The numerical simulation model of underhood was established,and the three-dimensional geometric model of the researched vehicle was simplified and meshed by using ANSA and Fluent software.A 1:1 proportional grid model with relatively high accuracy and the corresponding wind tunnel model were built.And the setting methods and reasons of boundary conditions were also described.(2)The influence of the cooling modules layout on the heat dissipation performance of the researched underhood was studied.? The flow field and temperature field of the original layout in high speed condition and simulated climbing conditions were studied.The results show that the distribution of the whole flow field under the hood can be improved.? The effects of two kinds of configuration of CRFM and CFRM on the heat dissipation performance of the underhood under high speed condition were analyzed.?The influence of the distance between the condenser and the radiator,together with the distance between the fanand the radiator,on the air inlet of the radiator were analyzed under the CRFM configuration.?According to the results of the orthogonal test of three factors and three levels,the optimal layout of the cooling modules was put forward,and the cooling air intake of the radiator is increased by 9.6% and 11.36% in high speed and simulated climbing conditions.(3)The optimization scheme was verified by experiments.The thermal balance tests of the original car and the improved prototype after moving the fan backwards under two extreme conditions were carried out respectively to evaluate whether the heat dissipation performance of the underhood met the design requirements,and the simulation results were compared with the real situation.? The results show that the cooling performance of the cooling modules can meet the design requirements,and the temperature of the various parts are not exceeded under two conditions.?The experimental data show that the air intake data obtained by the simulation analysis are basically the same as the data obtained from the test,and the errors are within ± 6%,which verifies the accuracy of the simulation data.And it is also possible to deduce that the optimization scheme of the cooling modules layout obtained by orthogonal test is feasible.