Numerical Simulation And Test Study Of Car Louvered Fin Radiator Performance

The radiator is the most important component of a vehicle cooling system,and its performance directly affects the engine’s operating performance.Therefore,the study of radiator performance is strengthened by modern design theory and analytical methods,which can provide theoretical basis and technical support for radiator design.After briefly introducing the basic theory of fluid mechanics and heat transfer,in this paper,combined with the parameters of an automobile engine and the actual loading conditions,the matching design of a louvered fin radiator is completed,and the rationality is checked.Then,the heat transfer model of louvered fins and radiator was established and simulated,and the heat transfer and flow resistance performance of the air side of the radiator were obtained under various typical working conditions,such as temperature,velocity and pressure cloud diagrams,and the simulation results showed that:as the air inlet velocity increased,the heat transfer coefficient of the radiator surface increased,and the heat dissipation capacity becomes stronger,while the pressure drop also gradually increases,and the flow resistance of the air side of the radiator increases.Finally,the louvered fin radiator is simplified into an overall CFD heat transfer model with porous media domain,cooling media domain and air domain,and numerical simulation analysis is carried out in depth,and the results show that:the heat dissipation capacity of the radiator increases with wind speed or water flow,the pressure drop of the air side of the radiator is only related to the wind speed,and the pressure drop on the liquid side of the radiator is only related to water flow,and the wind speed on the cooling volume of the impact is much greater than the water flow.In order to verify the validity of the simulation results,the prototype of the louvered fin radiator was made and the wind tunnel test was conducted.20 working conditions with air velocity of 2m/s,4m/s,6m/s,8m/s,10m/s and coolant flow rate of 40L/min,70L/min,100L/min and 140L/min were selected,and the results of the numerical simulation and the wind tunnel test were compared and analyzed by quoting the evaluation indicators such as heat transfer coefficient hf,heat transfer factor j,friction factor f and comprehensive performance evaluation factor j/f1/3 on the air side of the radiator,the error of heat transfer coefficient hf is 3.8%～8.6%,error of heat transfer factor j is 5.2%～8.7%,error of friction factor f is 1.5%～12.9%,the maximum error of comprehensive performance evaluation factor j/f1/3 without quantity is 6.2%～10.3%,all within the error allowed,the simulation results are in good agreement with the test data.Finally,a new type of perforated fin is designed in the paper,which can effectively reduce the flow resistance on the air side.Compared with the traditional louvered fins,the new perforated louvered fins heat transfer factor j increased by 4.2%～11.7%,friction factor f decreased by 5.1%～16.6%,comprehensive performance evaluation index JF increased by about 9.2%～12.2%;under the working conditions of wind speed of 6m/s and water flow rate of 100L/min,the liquid side of the radiator outlet temperature effectively decreased by 1.1℃,improving the heat transfer performance of louvered fin radiator.