液力变矩器流场仿真与快速原型技术研究

发布时间：2018-02-05 01:20

本文关键词： 液力变矩器流场分析数值模拟快速成型　出处：《扬州大学》2016年硕士论文　论文类型：学位论文

【摘要】：液力变矩器是车辆或工程机械传动系统中关键部件之一,其基本作用是通过工作液的流动实现能量的传递,同时起到改变转矩的作用。液力变矩器内部流场情况的好坏直接影响到传动系统的效率,因此,研究分析其内部流场分布规律具有一定的理论意义和应用价值。针对液力变矩器在设计开发过程中存在因大量试验而反复试制的问题,本文以液力变矩器为研究对象,通过建立三维模型,对其内部工作流场进行数值模拟,对比分析了两种不同工况下内部流场分布的规律和特性；针对叶片的形状复杂性,研究了基于光固化立体成型技术的液力变矩器叶片的快速原型工艺,并通过正交试验方法寻求最优加工方案,为快速原型技术在液力变矩器开发过程中的应用提供技术基础。叶片的形状是决定液力变矩器性能的最关键因素,本文通过深入分析液力变矩器叶片的多种设计理论和设计方法,阐述了多种设计方法的适用条件,并且运用逆向设计方法获得变矩器叶片的三维模型,并借助三维软件技术,建立了流道模型。然后基于流体力学的理论知识和方法,阐述了对液力变矩器内部流场进行数值模拟计算和研究的理论方法,为深入研究分析其内部流场特性提供理论依据。运用三维软件分别建立了液力变矩器三个工作轮的全流道模型,然后通过分割面切割出单个流道模型,设置周期性边界条件、壁面等,得到理想的离散型网格即计算模型。将计算模型导入流场分析软件中,选用合适的湍流模型和离散格式,定义工作液的参数,再次进行流体域及边界条件的设置,将上下游流道对应的进出口面进行配对,设置周期性边界条件为旋转,设置合适的收敛条件,进行两种工况下的流场数值计算。根据仿真软件计算结果,研究了上述工况下,各个流道进口面、中弦面、出口面的速度和压力分布以及叶片压力面和吸力面上的压力分布,得到了相关流场特性,并对其形成机理进行分析。鉴于液力变矩器内部流场的独特性和复合型,准确反映内流场状况的理论不完善,在开发设计过程中需要做大量试验的特点,提出了将快速原型技术应用于液力变矩器设计开发过程中,采用立体光固化快速原型技术,开展了液力变矩器叶片快速原型正交试验研究,选择叶片粗糙度、叶片质量、成型时间作为评价叶片快速原型影响因素的指标。对试验结果进行分析,得出各项因素对评价指标的影响规律,并且根据正交试验结果得出最优加工工艺方案,为快速原型技术在液力变矩器开发过程中的应用提供了技术基础。
[Abstract]:Hydraulic torque converter is one of the key components in the transmission system of vehicle or construction machinery. Its basic function is to transfer energy through the flow of working fluid. At the same time, the torque is changed. The flow field in the torque converter has a direct impact on the efficiency of the transmission system. It has certain theoretical significance and application value to study and analyze the distribution law of internal flow field. In the process of design and development of hydraulic torque converter there are problems of repeated trial and manufacture due to a large number of tests. In this paper, the hydraulic torque converter is taken as the research object. Through the establishment of a three-dimensional model, the numerical simulation of the internal workflow field is carried out, and the law and characteristics of the internal flow field distribution under two different working conditions are compared and analyzed. Aiming at the complexity of blade shape, the rapid prototyping process of hydraulic torque converter blade based on light solidification solid molding technology was studied, and the optimal processing scheme was found by orthogonal test method. It provides the technical foundation for the application of rapid prototyping technology in the development of hydraulic torque converter. The shape of blade is the most important factor to determine the performance of hydraulic torque converter. Through in-depth analysis of the various design theories and design methods of hydraulic torque converter blade, the application conditions of various design methods are expounded, and the 3D model of torque converter blade is obtained by using reverse design method. Based on the theoretical knowledge and method of fluid mechanics, the numerical simulation calculation and research method of flow field in hydraulic torque converter are described. In order to provide the theoretical basis for the in-depth study and analysis of the internal flow field characteristics, three dimensional software was used to establish the full channel model of the three working wheels of the hydraulic torque converter, and then a single flow channel model was cut out by dividing the surface. Setting periodic boundary conditions, wall surface and so on, the ideal discrete mesh is obtained. The calculation model is imported into the flow field analysis software, and appropriate turbulence model and discrete scheme are selected to define the parameters of the working fluid. The fluid domain and the boundary conditions are set again, the inlet and outlet surfaces corresponding to the upstream and downstream channels are paired, the periodic boundary conditions are set for rotation, and the appropriate convergence conditions are set. According to the results of the simulation software, the inlet surface and the middle chord surface of each channel under the above conditions are studied. The velocity and pressure distribution on the outlet surface and the pressure distribution on the blade pressure surface and suction surface are obtained, and the characteristics of the related flow field are obtained. In view of the unique and complex flow field in the hydrodynamic torque converter, the theory of accurately reflecting the internal flow field is not perfect, and a large number of experiments are needed in the development and design process. In this paper, the rapid prototyping technology is applied to the design and development of hydraulic torque converter. The orthogonal experiment of rapid prototype of hydraulic torque converter blade is carried out by using stereoscopic light curing rapid prototype technology, and the blade roughness is selected. Blade quality and forming time were used as indicators to evaluate the influencing factors of blade rapid prototyping. The experimental results were analyzed and the influence law of each factor on the evaluation index was obtained. According to the results of orthogonal test, the optimal processing scheme is obtained, which provides the technical basis for the application of rapid prototyping technology in the development of hydraulic torque converter.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH137.332

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