Abstract: The vehicle emission environment simulation chamber is used for the high and low temperature performance test of the vehicle, and the flow field distribution in the environment chamber is very important to evaluate the vehicle performance. In this paper, experimental and numerical simulation methods are used to analyze the differences of vehicle flow field in an emission environment simulation chamber, wind tunnel and open road. The results show that the vehicle emission environment simulation cabin has obvious blocking effect compared with the vehicle wind tunnel, which has significant influence on the roof pressure distribution, cabin cooling and chassis flow field, and the surface velocity of the radiator in the cabin is 19% lower than that on the road; and the velocity deviation of the chassis flow field from front to back gradually decreases, with the maximum deviation near the front suspension reaching 50%, and the deviation near the tail row is at least 10%. The results can provide useful reference for evaluating the cooling performance of the cabin, the comfort performance of the cabin and the thermal damage performance of the chassis by using the emission environment simulation cabin.

Key words: Emission environment simulation chamber; Wind tunnel test; Computational fluid dynamics; Numerical simulation; Open road; Flow field difference

摘要： 汽车排放环境模拟舱用于汽车高低温性能试验，环境舱内流场分布对评估汽车性能非 常重要。文章采用试验与数值仿真的方法分析了汽车在某排放环境模拟舱、风洞和开放道路 三种环境下的流场差异。结果表明，汽车排放环境模拟舱相对于整车风洞具有明显的阻塞效 应，其对车顶压力分布、机舱冷却及底盘流场均有显著影响，其中机舱内散热器表面速度相 比道路低 19%；车辆底盘从前向后的流场速度偏差逐渐减小，前悬附近偏差最大达 50%，尾 排附近偏差最小为 10%。该结果可为利用排放环境模拟舱评估汽车机舱冷却性能、乘员舱舒 适性能、底盘热伤害性能提供有益参考。

关键词: 排放环境模拟舱；风洞试验；计算流体动力学；数值仿真；开放道路；流场差异