【摘要】 为了提高发动机的冷却效率、降低高温零件的热负荷、实现整机的热量合理分配与利用,针对冷却水套优化设计中存在的冷却液三维流动与传热问题,以直列4缸发动机为研究对象,利用流固耦合的方法确定冷却水套壁面的传热边界条件,采用计算流体动力学软件AVL-FIRE对发动机冷却系统进行三维数值模拟,并对冷却水套内冷却液的流场分布、温度分布、壁面换热系数、各缸冷却均匀性和压力损失进行了分析.在此基础上,为了实现发动机冷却水套三维流场形态的可视化,构建了与实际冷却水套三维尺寸成1∶1的水套试验件模型,结合其结构特点讨论了试验件的制备方案,并对模拟工况下试验件的强度与管路系统的压力损失进行了验证计算,从而进一步为冷却水套的优化设计提供了理论与试验依据.更多还原

【Abstract】 For improving the engine cooling efficiency and reducing thermal load of high temperature components to realize the rational heat distribution and utilization,a numerical simulation of engine cooling system with computational fluid dynamics software AVl-FIRE was carried out for a four-cylinder engine to simulate the three-dimensional flow and heat transfer of cooling water in the engine jacket for optimization design.During the calculation,the heat transfer boundary of water jacket was determined following coupled liquid-solid theory,and the flow field of cooling water,the heat convection coefficient of the inner wall,the cooling uniformity of each cylinder and the whole pressure loss for the engine were analyzed.To realize the visualization of 3D flow field of the engine coolant,one to one scale 3D experimental part model of cooling jacket was constructed and its preparation scheme was also discussed according to the structural characters.Then the structural strength and pressure loss of the piping system were also simulated to verify the rationality of the design scheme.更多还原