SUV车型机舱冷却性能仿真分析与优化

针对某SUV车型中低速爬坡工况时发动机水温偏高问题,应用一维与三维联合仿真方法对车辆进行数值仿真分析,并对仿真的精准性进行试验验证。通过建立三维整车模型,对机舱进行冷流场计算,结合一维仿真发现发动机出水温度偏高,未能满足设计要求。对机舱内流场进行分析,发现冷却模块前端进气通道存在明显涡流、流动死区的现象。提出调整格栅开口比和增加前端导风板改善前段气流状况的方案,并进行整车热平衡试验验证仿真的有效性。结果表明:优化改进后散热器的进气量提高0.147 kg/s,发动机水温下降了8℃,仿真误差为2%,满足设计要求。

Simulation Analysis and Optimization of Cooling Performance of an SUV Engine Compartment

Aiming at the problem of high engine water temperature in a low-speed climbing condition of an SUV model,a one-dimensional and three-dimensional co-simulation method was applied to numerically simulate the vehicle,and the accuracy of the simulation was tested and verified.Through the establishment of a three-dimensional vehicle model,the cold flow field of the engine room was calculated,and the one-dimensional simulation software was used to calculate that the engine outlet water temperature was too high,which failed to meet the design requirements.Through the analysis of the flow field in the engine room,it is found that there are obvious eddy currents and flow dead zones in the air intake channel at the front of the cooling module.It was proposed to increase the front-end air deflector to improve the airflow in the front section,and conduct a vehicle thermal balance test to verify the effectiveness of the simulation.The results show that after the optimization and improvement,the air intake of the radiator is increased by 0.147 kg/s,the engine water temperature is decreased by 8℃,and the simulation error is 2%which meets the design requirements.