基于CFD技术汽车发动机冷却系统匹配性设计

Matching Analysis of the Cooling System of Vehicle Engine Based on Computational Fluid Dynamics

良好的冷却系统是保证发动机高效工作的重要保证。根据汽车发动机冷却系统的设计要求与基本的传热理论,对某款汽车发动机冷却系统进行设计,对选型设计、散热器风扇的匹配等进行分析,提出了匹配的评价依据。建立风扇、散热器的CFD模拟仿真分析模型,对风扇、散热器及二者匹配性进行模拟分析,并分析串并联布置散热器的差异。结果可知:对所设计风扇、散热器及二者的匹配进行校核,高低温散热器的实测散热系数与理论散热系数之比均大于1,表明设计合格,满足要求;串联散热器虽然散热效率稍高,但是由于发动机一泵两路的散热形式,并联形式的散热器适用范围更广,对高温恶劣情况的耐用性更好;最佳工况校核表明,冷却水由入口处的95℃下降到出水管处的大约平均78.2℃,满足发动机使用要求;分析结果的一致性表明分析的准确性和可靠性,为同类设计提供参考。

Good cooling system is an important guarantee to ensure efficient engine operation.According to the design requirements of the automotive engine cooling system and the basic heat transfer theory,a car engine cooling system was designed.The selection design and the matching of the radiator fan were analyzed,and the evaluation basis of the matching was proposed.The CFD simulation analysis model of the fan and radiator was established,the matching between the fan and the heat sink was simulated and analyzed,and the difference between the series and parallel arrangement of the heat sink was analyzed.The result shows that the matching fan,heat sink and the matching between them are checked.The ratio of the measured heat dissipation coefficient of the high and low temperature radiator to the theoretical heat dissipation coefficient is greater than 1,indicating that the design is qualified and meets the requirements.Although the heat dissipation efficiency of the series heat sink is slightly higher,But because the pump of engine has two ways of heat dissipation form,the parallel type radiator has a wider application range and better durability against high temperature and adverse conditions.The best condition check shows that the cooling water drops from 95℃at the inlet to an average of 78.2℃at the outlet,meeting engine requirements.The consistency of the analysis results indicates the accuracy and reliability of the analysis and provides references for similar designs.