基于simple算法湍流场计算机仿真.pdf

安徽大学硕士学位论文基于SIMPLE算法的湍流场的计算机仿真姓名:占惊春申请学位级别:硕士专业:计算机应用技术指导教师:汪继文 20070401 安徽大学学位论文摘要摘要湍流问题曾被称为“经典物理学最后的疑团”,是流体力学中尚未解决的最复杂的理论之一。湍流是一种在任一空间点的瞬时物理量都在作剧烈变化的随机运动,在湍流中存在无序的小尺度脉动结构和具有某种次序的大尺度旋涡结构(拟序结构) 的复合结构。在工程流动、化工反应、传热和扩散等领域都涉及对湍流场数值模拟的问题,极为困难,其中我们关心的是控制区域里速度、压力、温度以及相关的动量、能量等值,以及其随环境变量的变化情况。要反映湍流流场的真实情况,目前数值模拟主要有三种方法:①平均N—S 方程的求解(RANS),②大涡模拟(LES),③直接数值模拟(DNS)。但是由于机械结构内部的复杂性以及目前计算机运行速度较慢,大涡模拟和直接数值模拟还很少用于湍流场的计算,更多的是通过求解平均N—s方程来进行数值模拟。因为平均N—S方程的不封闭性,需要引入湍流模型来封闭方程组。在这种背景下,为实现对湍流场精确的数值计算,,周培源提出k一占双方程模型,获得最普遍使用。在该模型中湍流流动的各个物理量可用通用方程组统一表达。本文采用双方程模型对湍流场数值模拟这一工程难题做了研究。求解思路是在SIMPLE算法的基础上,结合Vc++软件开发与MATLAB数值计算的优势,调用MATLAB Engine混合编程,实现对湍流场的数值计算。文中结合湍流场二维流动的问题,展示了数值模拟的结果。关键词:湍流SIMPLE算法计算机仿真 Abstract Turbulence has been known aS“the final mystery in classical physics”,which iS the plex theories in unsolved CFD. Turbulence is a kind of random turbulence,tbere posite structure with disorder smal卜scale pulse structure and the large—scale structure of the vortex structure(coherent structure).It is first found by Reynolds and proved in experiment in 1883. There issomething to do with the numerical simulation of turbulent flow in project flow, chemical reaction,heat intersection and is we concern in speed,pressure, temperature’momentum, energy and the changes made by environmental variables. To show the fact in turbul ence flow,there are 3methods:①RANs, ***@large eddy simulation,LES,③Direct Numerical Si舢lation,DNS。 Because of plexity in mechanical structure and the low sDeed puter,LES and DNS is not used in the numerical simulation of turbulent model is used to make the Navier—stocks equations closed. k一占Turbulence Model and its two—equation mode have been essfully used for turbulent flow analysis, and make the hasic turbulent flow equations of mass,momentum,energy can be expressed algorithm is the most important method for the numerical simulation of fluid advantage of VC’S powerful programming developmen