【作者】 陈见；

【导师】 过学迅；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2008， 硕士

【摘要】 本文的研究为“车辆传动国家重点实验室基金项目”中的一部分,以D375型液力减速器为研究对象,基于三维流场理论,借助于UG、FLUENT等软件,对液力减速器的内流场进行了仿真计算,获得了特性曲线,同时将计算的结果与试验的结果进行了比较。本课题研究的目的和意义就在于,利用CFD技术研究液力减速器内部的流动及规律,有助于指导液力减速器的设计,提高液力减速器的性能,同时对拥有自主研制开发生产液力减速器有一定的帮助,对我国的经济发展也具有重大的意义。本文首先介绍了课题研究的背景,液力减速器在国内外的应用情况和流场理论的发展现状,介绍了常用的CFD软件,并选择FLUENT对本课题进行研究,然后对液力减速器的结构和工作原理进行了阐述,最后提出了主要研究的内容。分析了液力减速器内流场仿真所涉及到的计算流体力学基本理论。详细介绍了常用的离散格式和网格的生成技术,分析了常用的湍流模型,湍流流动的近壁处理方法和流场数值计算的算法。根据所做的假设,采用UG抽取液力减速器的流道模型,为了提高计算精度,采用映射法划分六面体网格,选择分离求解器隐式格式进行求解,使用绝对速度方程,湍流模型选择Realizablek-ε模型,同时使用标准壁面函数;离散格式采用一阶迎风格式,压力—速度耦合选用SIMPLE算法,在相应的位置设置壁面边界条件、滑移网格边界条件。计算收敛后,对某工况下内流场的速度、压力分布进行了详细的分析。分析了液力减速器三维流动分析中的转矩计算,并将三维计算值与一维束流理论值以及试验测量值进行了比较,证明了三维计算的准确性,对部分参数进行了优化,在此基础上探讨了基于CFD技术的液力减速器设计方法。本文的研究对液力减速器内部流动特性有了更加清楚的认识,对提高液力减速器自主研发有一定帮助,为建立基于CFD技术的新设计方法提供了思路,为下一步的研究指明了研究方向。更多还原

【Abstract】 The research is a part of national fund project of key laboratory of the vehicle transmission.The internal flow field of the hydrodynamic retarder D375 is simulated by UG and FLUENT etc,characteristic curve is obtained based on 3-D flow field theory.Test results and simulated results are compared.The research has been used the CFD technology to study the internal flow and principle of hydrodynamic retarder, and the purpose is to guide the design of hydrodynamic retarder and improve its performance,meanwhile,for the independent research and development.It has significant meaning to economic growth of our country.Firstly in this paper,the background of subject research and the application of the hydrodynamic retarder in the world have been introduced.The current situation of the development of the field flow theory has been listed.Some CFD software has been introduced and CFD software FLUENT has been chosen to carry on this research,then structure and operation principle of the hydrodynamic retarder have been explained and main contents of this research has been introduced.This paper has analyzed the basic theories of CFD in this research.Then introduced the discrete scheme,creation technology of the grid and turbulent model in detail,introduced the method of near wall treatment methods and the algorithm of calculating field flows.The geometric model is created by UG,based on some assumptions and predigestion.Grid is created by mapping method,in order to improve the precision of calculating,using the grid of hexahedron.The realizableκ-εmodel,SIMPLE velocity-pressure coupling algorithm,separated solver,the implicit scheme model and the standard wall function has been chosen,and boundary conditions have been set up, such as wall boundary condition and sliding meshes condition.When the convergence achieved,this paper has made deeply analysis with velocity field and pressure field under some operating condition.The results of calculation has been analyzed and compared with those of experiment and the beam fluid theory,which proved the validity of three-dimensional calculation. This research has achieved more and clearer understandings of the internal flow and principle of hydrodynamic retarder which can do some help for the independent research and development of retarder.A new design method of retarder based on CFD technology has been carved out which point out the orientation for the farther research.更多还原