基于CFD技术的湿式摩擦片仿真分析研究

发布时间：2018-06-05 19:22

本文选题：湿式双离合器 + 湿式摩擦片　；参考：《吉林大学》2011年硕士论文

【摘要】：湿式双离合自动变速器具有传统机械式变速器的传动效率高、安装空间紧密、质量轻便,并且同时拥有自动变速器换档平顺、燃油经济性较高等优点。湿式双离合器在国内发展时间较晚,正处在一个学习与探索的阶段,但是随着我国改革开放的进一步深入,对于汽车行业的发展也越来越重视。因此,我们通过借助国外的一些先进经验,更深层次的学习和研究湿式双离合器技术,为我国自动变速器的自主开发提供更多的参考依据。本文以吉林省科技发展计划项目《汽车关键核心技术(吉林省汽车自主创新联合行动)》为依托,吉林省科学技术厅委托吉林大学承担吉林省科技发展计划中的双离合器自动变速器(DCT)开发关键技术项目的科研任务。本文结合该项目重点对湿式双离合器摩擦片油槽的流场特性分析进行深入研究,通过计算流体力学仿真软件对冷却油在摩擦片三种典型油槽的内流场和主、从动摩擦片的对流换热情况进行仿真分析并对带排扭矩进行计算。文章正文内容共分为五个部分来叙述：第一部分通过湿式双离合器自动变速器的结构与工作原理,了解湿式摩擦片的工作环境。基于对当前国内外湿式双离合器自动变速器的发展需求,结合省厅的湿式双离合器(DCT)关键技术开发的科技项目,了解到当前国内外的专家、学者越来越关注湿式摩擦片表面沟槽对于摩擦片摩擦特性的影响,但是基于计算流体力学技术的研究却很少。介于这种情况,提出本文研究内容的思想,利用计算流体力学技术对冷却油在摩擦片表面沟槽的流场特性进行仿真分析。第二部分基于计算流体力学技术,为本文的流场分析以及对流换热提出数学计算模型。湿式离合器内冷却油可看成一种三维非稳态、带旋转的不规则湍流流动。流场数值计算的本质就是对离散后的控制方程组进行求解,即对控制方程在控制区域内进行积分以建立包括各种相关离散变量的代数方程组,然后进行求解。而摩擦片破坏方式多为高温引起摩擦偶件的变形、开裂或烧蚀,冷却油液在摩擦片表面沟槽内与主、动从摩擦片之间的热交换情况,也成是本文研究的一个重点。第三部分主要是搭建摩擦片油槽流场特性仿真模型。利用三维制图软件UG,创建三种典型油槽结构。然后导入网格划分软件Gambit中进行模型简化,并且对单元类型、网格类型、边界类型、区域类型及其他相关选项设置后进行网格划分,最终得出与求解域完全对应的网格模型。第四部分利用计算流体力学软件Fluent分别对径向油槽、方形槽、太阳射线槽进行内流场和对流换热的仿真分析。并且根据速度矢量值和温度值来对比三种油槽的流场特性的优劣。第五部分委托摩擦片生产单位试制径向油槽摩擦片并进行台架试验,分别为定输入转速,变进口流量和定进口流量,变输入转速两种工况进行数据采集,并与仿真结果的对比,验证仿真结果与试验结果基本吻合。针对湿式离合器工作状况的模拟,利用计算流体力学仿真软件得出的数值结果,对于湿式离合器摩擦片的研究具有很高的参考价值。最后进行全文总结,介绍了工作中遇到的重点、难点,并且指明此次仿真结果的不足,提出今后进一步研究的方向。
[Abstract]:The wet double clutch automatic transmission has the advantages of high transmission efficiency, tight installation space and light quality, and also has the advantages of smooth shift gear and high fuel economy at the same time. The wet type dual clutch is developing late in China and is in a stage of study and exploration, but with the reform of our country With the further development of the opening, more and more attention has been paid to the development of the automobile industry. Therefore, through the use of some advanced foreign experience, we can study and study the wet double clutch technology in a deeper level, and provide more reference for the autonomous development of the automatic transmission in China.
Based on the Jilin provincial science and technology development project, the key core technology of automobile (Jilin auto innovation joint action), the Department of science and technology of Jilin commissioned the Jilin University to undertake the research task of the key technical project of the development of the dual clutch transmission (DCT) in the science and technology development plan of Jilin province. This paper combines the key points of the project. The flow field characteristic analysis of the wet double clutch friction plate oil tank is deeply studied. Through the calculation of the fluid mechanics simulation software, the internal flow field of the cooling oil in three typical oil grooves and the convection heat transfer of the main and the driven friction plate are simulated and calculated. The content of the article is divided into five parts. To describe:
In the first part, through the structure and working principle of the wet double clutch automatic transmission, the working environment of the wet friction friction disc is understood. Based on the development requirement of the current wet double clutch automatic transmission at home and abroad, and the scientific and technological project developed by the key technology of the wet double clutch (DCT) in the provincial office, the experts and scholars at home and abroad are understood. More and more attention is paid to the influence of the surface grooves on the friction characteristics of the friction plates, but the research based on computational fluid mechanics is very few. In this case, the idea of the content of this paper is put forward, and the flow field characteristics of the cooling oil in the surface groove of the friction plate are simulated and analyzed by the computational fluid dynamics.
The second part is based on the computational fluid dynamics (CFD), and proposes a mathematical model for the flow field analysis and convection heat transfer in this paper. The internal cooling oil in the wet clutch can be regarded as a three-dimensional unsteady, irregular turbulent flow with rotating. The essence of the numerical calculation is to solve the discrete control equations, that is, the control equation is in the control equation. In the control area, the integral in order to establish a set of algebraic equations including a variety of discrete variables is established and then solved. The failure mode of the friction disc is mostly caused by the deformation, cracking or ablation of the friction pairs. The heat exchange between the cooling oil in the groove surface of the friction plate and the main motion from the friction plate is also a study of this paper. Focus.
The third part is mainly to build the simulation model of the flow field characteristics of the oil tank of the friction plate. By using the 3D graphics software UG, three typical oil groove structures are created. Then the grid partition software Gambit is introduced to simplify the model, and the grid type, the grid type, the boundary type, the region type and the other related options are set up, and the final mesh is divided, finally, the grid is divided. A mesh model which is completely corresponding to the solution domain is obtained.
In the fourth part, the computational fluid dynamics software Fluent is used to simulate the internal flow field and the convection heat transfer of the radial oil tank, the square groove and the solar ray slot, and the flow field characteristics of the three kinds of oil tanks are compared according to the velocity vector value and the temperature value.
The fifth part of the production unit of the entrustment friction plate produces the radial oil tank friction plate and carries on the bench test. The data collection is carried out for the fixed input speed, the variable inlet flow rate and the fixed inlet flow rate and the variable input speed, and compared with the simulation results, the simulation results are basically consistent with the test results. The working shape of the wet clutch is done. The numerical results obtained from CFD simulation software have a high reference value for the study of wet clutch friction disc.
Finally, the paper summarizes the main points and difficulties encountered in the work, and points out the shortcomings of the simulation results, and puts forward the direction for further research.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH132.46

【参考文献】