【作者】 常华；

【导师】 郭晓平；

【作者基本信息】 大连理工大学 ， 动力工程， 2012， 硕士

【摘要】 内燃机的工作过程是一个包含有流体运动、流体传热传质、化学反应以及它们之间互相作用的复杂的物理化学过程。而采用数值模拟方法对其进行模拟,优势在于周期短,成本低,快捷方便,信息量大,适用性强,能充分反映几何和其他特性的影响,国内和国外的许多单位对它进行了深入的研究,并取得了骄人的成绩。其中,美国Los Alamos实验室的KIVA系列软件是已开发出的最具代表性的。作为最具代表性的内燃机燃烧的KIVA仿真程序,它采用任意朗格朗日-欧拉法(ALE)进行有限差分计算,利用任意六面体网格单元对控制变量进行空间离散求解,使得程序在计算对象的几何适应方面有很强的功能。KIVA含有的自动生成网格的子程序K3prep,可以生成一定形状的活塞和任意形状燃烧室网格,但此程序的网格生成算法存在一定的缺陷,当气门与燃烧室轮廓同时存在于气缸内网格时,他们轮廓的重合点需要手动从输入文件中输入准确的物理坐标值,这就使得在网格生成过程中人为的计算量急剧增加,降低了实用性,为此本文对其网格生成算法进行了改进。现代内燃机正快速发展,涡轮增压发动机逐步走向主流,而涡轮增压发动机的增压效果,除了良好的设计,依靠涡轮增压器,在很大程度上也取决于发动机排气系统的设计。但是,K3prep中对进排气道的网格生成子程序相对简单,当面对较复杂的排气系统时,K3prep便难以胜任,它不能够生成规则的与气缸轴线相垂直的圆柱气道网格,为此本文对其网格生成进行了适当的改进,、使之能够应用到实际。经使用发现,改进后的网格生成过程有效的消除了四气门带凹坑燃烧室网格的畸变,从而使收敛加快,计算结果更加准确。气道网格生成算法的改进,以便它可以模拟运动气缸内的气体流动和气阀的升程规律。更多还原

【Abstract】 The internal combustion engine work process is a fluid motion, fluid heat and mass transfer, chemical reactions and the interaction between them complex physical and chemical processes. Numerical simulation method to simulate the advantage of a short cycle, low cost, fast and convenient, informative, and applicability, can fully reflect the geometry and other characteristics of domestic and foreign many units it in-depth research, and has made remarkable achievements. Among them, the Los Alamos Laboratory KIVA family of software has been developed the most representative.KIVA uses the arbitrary hexahedron grid units to solve control variables to space discrete model. It makes the program of the object in the calculation of the geometric settle have very strong function. It can calculate the shape of the piston and certain arbitrary shape the combustion chamber. But the program of grid generation algorithm has some shortcomings. Four valve pits of the combustion chamber of the grid are not adapted. This paper on the grid generation algorithm was improved.With the rapid development of modern internal combustion engine development, turbocharged engines tend to the mainstream of the era. Exhaust system design on engine exhaust the use of energy has an important effect. While the KIVA grid generation program has certain blank. The exhaust duct of grid generation has some shortcomings. It can’t make the exhaust main to a tube shape in the crowded gas area. This paper makes an improvement on the grid generation for the appropriate. Make it more accord with the actual.By the use of found, the improved grid generation process effectively reduce Or Even Eliminate Four valve pits of combustion chamber with grid distortion. So the convergences speed up. The calculation results more accuracy. Improve the airway grid generation algorithm. So it can simulate the influence of airway and valve movement rules in cylinder of gas flow and the influence of combustion.更多还原