Abstract: The engine cooling system is matched with the overall vehicle development, and various car manufacturers have different water parts flow resistance characteristics, pipe layouts, and water outlet positions, which greatly affect the water flow distribution. In order to explore the influence of various variables on the system-level water flow, this article conducts relevant simulation research. By building a one-dimensional simulation model of the cooling system to obtain the water flow of each water accessory, the article analyzes the influence of each variable on the distribution of branch water flow. Using the Flowmaster software, the article builds a one-dimensional simulation model of the cooling system with a single thermostat and a dual thermostat, and compares the effects of single and dual thermostats on the cooling system's water flow distribution. It also validates the accuracy of the simulation model and the rationality of the simulation method by comparing the measured water flow of single and dual thermostats. Through this model, the article verifies the influence of pipe length, inner diameter, bending number, and water inlet and outlet positions, etc., on branch water flow, providing reference for subsequent cooling system branch design and homologation.

Key words: six-cylinder engine; cooling system; dual thermostat; branch flow; numerical simulation

摘要： 发动机冷却系统在匹配整车开发时，各个主机厂配套不同车型，用水部件流阻特性、 管路布局、水口位置等存在极大差异性，影响水路流量分配。为探究各变量对系统级水流量 的影响，文章展开了相关仿真研究。通过搭建冷却系统一维仿真模型获取各用水附件的水流 量，并分析各变量对支路水流量分布的影响。采用 Flowmaster 软件，搭建单节温器及双节温 器的冷却系统一维仿真模型，对比单、双节温器对冷却系统流量分布的影响，并对标了试验 采集的单、双节温器的水流量，验证了仿真模型的准确性以及仿真方法的合理性。通过该模 型，验证了管路长度、内径、折弯数量以及取、回水位置等复合变量对支路流量的影响，为 后续冷却系统支路设计与视同放行提供了参考依据。

关键词: 六缸发动机；冷却系统；双节温器；支路流量；数值模拟