导　　师： 贾月梅

学科专业： 080103

授予学位： 硕士

作　　者： ;

机构地区： 太原理工大学

摘　　要： 发动机冷却水套内冷却液的流动直接影响着发动机的冷却效果、发动机的热量分配、高温零部件的热负荷以及能量的利用,同时冷却液的温度还对发动机废气的排放有着显著的影响。随着发动机增压等各种强化方法的采用,有效地改善发动机冷却循环系统已经成为发动机设计中的重要内容。其中,发动机冷却水套内冷却液流动的数值模拟便是目前研究发动机冷却水套冷却液流动和优化冷却水套结构的重要方法之一。 本文以北京现代α1.6型号四缸汽油发动机的冷却水套为研究对象,利用三维CAD软件UG建立了冷却水套的几何模型,并且在保证与原发动机冷却水套结构尽可能一致的前提条件下,对其进行了必要的简化处理。然后使用FLUENT的前处理软件GAMBIT对冷却水套模型进行了网格划分,最后用FLUENT软件对冷却水套的流场进行了数值模拟计算及结果的后处理分析。由模拟计算结果的分析可知该四缸发动机冷却水套的设计比较合理,基本能够达到设计要求的冷却效果,但其也存在一些需要优化的地方,主要表现在缸盖冷却水套内的冷却液流速不太大,温度分布不均匀,需进一步改进提高,以达到最优的冷却效果。为此本文提出三种发动机冷却水套的优化方案,并对优化后的发动机冷却水套流场进行了数值模拟计算。结果表明,优化后的发动机缸盖冷却水套内的冷却液流速得到较大幅度地提高,与此同时缸盖冷却水套流场的温度分布也更为均匀。 本文通过对该款发动机冷却水套的三维CFD数值模拟得到了大量冷却水套内的流场信息,为指导该款发动机冷却水套的优化设计提供了一定的参考依据。 With the continual development of science and technology,the methods of design in the engines and their component have significant transformed,and follows the enhanced design quality the performance of the engine also obtain unceasing enhancement. The affection of the coolant flow in engine’s cooling system focus on the cooling effective、heat load of the parts,the distribution and usage of heat energy. Meanwhile,the emissions of the engine are closely related to the coolant temperature. With the approaches to increase output power used perfectly improving cooling system have become the important tasks to design the original engines. Now,the numerical simulation of the flow and heat transfer in the engine water jacket becomes a principal method to optimum cooling system. This article has taken a section of Beijingα1.6 four cylinder gasoline engine water jacket flow field as the object for studying. Using the three-dimensional CAD software UG to establish the cylinder water jacket flow field geometry model, and has taken the essential simplification as far as the possible in the guarantee with the original water cavity consistent. The model is checked and meshed by the FLUENT front-processed GAMBIT, subsequently, the water jacket flow field are computed and displayed,and then the results are post-processed and analyzed all by FLUENT. By the simulation calculation of the flow field in water jacket of the four cylinder gasoline engine,the results show that the design is comparatively to be reasonable and can achieve the cooling effect. But it also has some deficiencies, mainly displays the speed of cooling liquid is not too large in the cylinder head water jacket、the distribute of the temperature is not uniformed, and they still had further to make the improvement. Therefore, this article use three improved programme and do the simulation calculation to the improved flow field of the water jacket. The results show that the speed of cooling liquid is increased largely in the cylinder head water jacket,

关 键 词： 发动机 冷却水套 流场 数值模拟

领　　域： [动力工程及工程热物理]