铸造充型过程的计算机模拟

【作者】 闫金；

【导师】 张希俊；

【作者基本信息】 昆明理工大学 ， 材料加工工程， 2004， 硕士

【摘要】 本文介绍了当前铸造充型过程数值模拟的发展现状和趋势，介绍了国内外主要的模拟软件，以及在研究过程中存在的主要问题。我国的计算机数值模拟领域与国外相比还有很大的差距，本文讨论了开发铸造充型过程数值模拟软件的必要性和重要性。本文在流体力学基本概念的基础上，以流体流动的三联控制方程组为基础，利用有限差分法推导出了充型过程的动量、能量差分格式。根据SOLA法和能量守恒建立了求解充型过程流场的程序流程图。在连续性方程流量平衡思想的指导下，对流体计算域的各种边界条件进行了假设，应用于充型过程的数值计算中。文中基于VOF法推导了一个简单有效的三维自由表面处理方法，可以计算表面网格的流量变化，并用于充型过程的数值模拟中。根据能量守恒定律和对流、传导热计算公式，建立了温度场耦合速度场的计算程序。本文采用面向对象编程方法和编程，利用Visual C++6． 0在Windows操作系统上开发了铸造充型过程数值计算软件。本软件以课题组已开发完成的凝固模拟软件为平台，在已具有前处理部分和后处理显示部分的基础上，进行充型过程温度场耦合速度场的数值计算，最终可得到充型完成时整个铸件的温度场分布及充型过程中的流动形态的图像显示。利用本文开发的软件所得的计算结果与试块铸件的实际充型情况进行了比较，两者基本相符，证明本文开发的软件可用于实际铸造生产过程。基本达到了课题的开发目的。更多还原

【Abstract】 The present situation and direction of simulation of mold filling in metal casting is described. This thesis introduces some software for simulation in the world. Some problems bringing out in the process of research are also described. In the field of simulation, our country is behind the developed countries, which is the main reason to develop our simulation software.According to the physical regulations of fluid flow of metal liquid, govern equations of mold filling in metal casting are described and mathematics model is built. This thesis derives the finite difference forms of govern equations which meet the demands of accuracy and stability of calculation. These finite difference forms of govern equations can conduct fluid flow analysis. On basics of the SOLA-VOF algorithm, flow chart of program is developed to solve the velocities of fluid flow. Boundary conditions are specified consistent with the philosophy of the continuous equation. With the VOF algorithm, a simple method is developed to specify the location and volume fraction of free boundaries grids.With Visual C++6.0, this thesis develops a software to calculate the velocities of filling metal in the casting. The OOP(Orient Object Program) and multithreading are used. On the preprocessor and postprocessor platform which has been developed, this procedure can solve the velocities and temperature of fluid dynamics, and the result can been displayed with the colorful images.The results got from this procedure are compared with the practical situation of mold filling. According to the compare, the results accord with the practical situation, which proved that this simulation program can been used to predict the mold filling in metal casting. The purpose of this thesis is reached.更多还原