Research On Matching Optimization Of Thermal Management Of A Car Cooling System

With the increasing number of various components in the engine compartment of the automobile,and the internal environment is getting worse.Therefore,the thermal management of the engine compartment has become the focus of researchers at home and abroad.The research content mainly includes the airflow characteristics in the engine compartment and the cooling capacity of the cooling system.Computer simulation technology can reduce development costs and reduce development cycle compared with experiments.In this paper,taking a rear-mounted exhaust car as an example,the following study carried out on the engine compartment and cooling system with using a combination of computer simulation and testing.1)In the software CFD,established the finite element model of the vehicle and calculated the flow field in the engine compartment.Then studied the air flow characteristics of the cooling system.Three-dimensional model of exhaust rear-mounted vehicle was pre-processed,including the simplification of the vehicle geometric model,the use of the surface wrapper and surface remesher to divide the surface mesh,and the Trim mesh sub-regional method to generate the volume mesh.Finally,calculated the flow field in the engine compartment under the climbing and high-speed conditions,and found that the environment in the engine compartment was relatively bad under the climbing conditions.2)The one-dimensional and three-dimensional coupling matching calculation can effectively evaluate the heat dissipation performance of the prototype cooling system.According to the experimental data provided by the enterprise and the 3D model calculated data were obtained the boundary conditions of the one-dimensional calculation model,and the one-dimensional numerical model of the engine cooling system is established.3D calculation Data transfer to one-dimensional.Then one-dimensional and three-dimensional coupled model of the climbing condition was obtained,and found the outlet temperature of the radiator was too low under this condition.3)For the temperature of the radiator is too low under the climbing condition.Change the layout of the condenser and radiator in the 3D model,the fan speed and the windward area of the radiator,and keep the other parameters of the cooling system unchanged.The one-dimensional and 3D coupling model of the established automobile engine cooling system was used to calculate the variation of the outlet temperature of the radiator in the range of lOm/s～40m/s.The optimal range of the three factors is obtained.The radiator is better behind the condenser,fan speed is better between 1400rpm and 1800rpm,the windward area of the radiator is better in the range of 600mm×450mmy650mm×450mm.Then the vehicle is subjected to a vehicle thermal balance experiment.The results show that the error between the simulation value and the test measurement result is small,meets the actual engineering requirements.Verifies the accuracy of the simulation calculation.