Abstract: In order to continuously optimize the vehicle thermal management performance of a commercial vehicle, improve the flow field of the vehicle, optimize radiation performance of the cooling system, the influence of different air guide devices on the flow field characteristics of the engine compartment are studied by using computational fluid dynamics (CFD) technology. The paper matches a 13 L gas engine on a heavy-duty commercial vehicle, through optimizing the positioning of the engine and wind shield structure, the influence of two types of wind shield on the engine compartment flow field are compared and analyzed, the pressure and velocity distribution inside the engine compartment, as well as the airflow and return flow through various positions of the cooling system are obtained, it can provide reference for optimizing the thermal management of the engine compartment. The results show that flow line in the engine compartment with the lower height wind shield is more uniform under rated conditions and high torque conditions, and the flow rate at each position of the cooling module increases to varying degrees, and the reflux decreases.

Key words: Thermal management; Radiator; Cooling system; Wind shield

摘要： 为持续优化某商用车型整车热管理性能，改善整车热流场、优化冷却系统散热性能， 利用计算流体动力学（CFD）技术针对不同导风装置对发动机舱流场特性的影响进行了研究。 文章在某重型商用车上匹配一款 13 L 燃气发动机，通过优化发动机定位及护风罩结构，对比 分析两种不同型式的护风罩对机舱流场的影响，得到了发动机舱内部压力、速度分布，流经 冷却系统各个位置的风量及回流情况，为优化机舱热管理提供参考。结果表明，优化后护风 罩在额定工况、大扭矩工况机舱内流场流线更均匀，且冷却模块各个位置的流量均有不同程 度的增加，回流均有所减小。

关键词: 热管理；散热器；冷却系统；护风罩