SUV发动机舱热管理一维/三维联合仿真与改进

在某款SUV正向研发阶段，为解决中低速爬坡和高速爬坡工况下发动机出水温度偏高的问题，利用一维/三维联合仿真工具，对模型进行发动机舱流场特性及冷却系统性能分析，发现现有防撞梁设计会影响进风量，从而影响发动机出水温度。基于仿真结果提出了改进方案，改进后发动机的出水温度在中低速爬坡和高速爬坡两种工况下分别下降了6.1 ℃和6.4 ℃，验证了联合仿真改进方案的可行性。样车阶段，在转毂试验台上采用大流量风机和轴流通风机来模拟汽车行驶过程中的来流空气，并对改进方案进行了整车热平衡试验。 通过对比改进后的仿真结果与试验数据，验证了联合仿真模型精度高于95%。

1D/3D Co-simulation and Improvements of Thermal Management for SUV Engine Compartments

During the forward R&D periods of a sport utility vehicle(SUV)，in order to solve the problems of engine outlet water temperature was rather higher in low or medium speed climbing and high speed climbing conditions, 1D/3D co-simulation tools were used to analyze the flow field characteristics of engine compartments and the performances of cooling systems. It is found that the design of the existing anti-collision beam affects the air flows and thus affects the engine outlet temperatures. An improved scheme was proposed based on the simulation results, the outlet water temperatures of improved engines are dropped 6.1 ℃ and 6.4 ℃ under the middle or low speed climbing conditions and high speed climbing condition respectively, and the co-simulation improved scheme is verified feasible. In the periods of the sample car，the vehicle thermal balance tests were performed on the chassis dynamometer, and the large mass flow fans and axial flow fans were used to simulate the inflow air during driving.  By comparing the improved simulation results with the experimental data, which verify the accuracy of the co-simulation model is higher than 95%.