Research Of Thermal Management And Cooling Performance Improvement Of Engine Compartment Of A Passenger Car

In the current world environment with increasing environmental pollution,decreasing non-renewable energy and gradually improving exhaust emission standards,engine thermal management technology has gradually evolved into an important inspection measure to ensure the normal operation of vehicles under extreme working conditions.With the rapid development of vehicle design and manufacturing technology,under the condition of satisfying sufficient power,comfort and economy,the vehicle has already been compressed into a precise moving tool,and the space in the engine compartment is continuously compressed,making a large number of electronic components and high power heating body are squeezed together,causing the key components to deform or fail due to the high working environment temperature,which undoubtedly puts a huge test on the engine compartment cooling performance.In order to improve the performance of the engine cooling system during the initial development of the product,the preliminary analysis results of the cooling efficiency of the engine cooling system are obtained,which provides a reference for the arrangement of the internal parts of the engine compartment of the subsequent model,so as to avoid multiple modifications,the time and financial waste caused in the later stage by the test and verification.Using the one-dimensional and three-dimensional co-simulation method,a systematic engine compartment cooling performance simulation analysis is carried out on a medium-sized passenger car,and the simulation and prototype test results are also carried out.The results were compared and the errors were all within 5%.The feasibility and accuracy of the process method were verified.The CFD simulation software was used to optimize the cooling system of the vehicle,and the structural layout problems of the engine room were provided.and improvement simulation results show that heat dissipation performance of the engine compartment has been improved,which can provide guidance for subsequent projects.The 1D software KULI was used to perform the steady-state simulation calculation of the engine cooling group.Through the bench test of the radiator,fan,intercooler and other components in the cooling system,various performance data in the bench test of each component,including the cooling performance parameter curve,structural parameters,etc.,and the modified boundary result in the 3D simulation,working condition data under the maximum torque and the rated power of the vehicle condition are input,and the calculation results of engine coolant temperature is obtained,Simultaneously,using results of prototype car under heat balance test to verify simulation accuracy,for various cooling effects,the one-dimensional simulation model of the matching of the four cooling system components is formed and calculated,the results show that it is better for the working balance of the engine water temperature to replace radiator.Finally,the three-dimensional fluid analysis software STARCCM+ is used to simulate the engine compartment.Through the results,the gas temperature and velocity distribution of the engine compartment are observed.It is considered that engine compartment temperature meets the regulatory requirements,the heat dissipation is moderate,and component design structure and arrangement method with heavier internal problems are found.By changing the shape of the square shroud to a triangular channel,the surface air intake of the radiator at high speed is increased by about 2%,and at low speed,it is decreased by 2.1%,but the reduction of the volume of the shroud increases the air movement in the engine compartment.Cabin temperature dropped significantly,and the advantages outweigh the disadvantages.And improvement measures are used by adding baffles,seals,and separation of heat sources.The internal airflow problem has been improved,effectively reducing the ambient temperature in the cabin.Provide reference for subsequent vehicle production,and better adapt to design requirements in higher temperature regions.