The Application Of Numerical Simulation On The Flow Field Of Hydrodynamic Torque Converter

The hydraulic torque convert is one of the most important parts in hydraulic transmission and it is composed of three rotor wheel, pump rotor, turbine and guide wheel. The fluid in interval channel is in the state of three-dimensional viscous time-dependent flow and so it is very difficult to analysis and observe the flow condition neither with theoretical method nor with tentative method. The computational fluid dynamics (CFD) grown up with the development of computer in the 1960s and after almost fifty years, its theorem and application all get mature. The most obvious symbol is the emergence of all sort of software of CFD and their purpose is solving the most classical equation of Navier-stokes. In this dissertation we will study the interval flow of hydraulic torque converter with UG and ANSYS software. But because of the limitation of computing method and the hypothesis in CFD, the result of the computing with software still have many place needing ameliorating. The first part describes the surrounding of the project and explains the object matter of this paper. Numerical simulation is also called computer simulation and it has many merit such as minor consume, small time-spending and saving manual and at the same time it can repeat computing and be easy controlling that is very important for cosmically simulation such as turbulence. In the start of the paper the development of numerical simulation and the application of it in flow field calculation and simulation are introduced; several soft wares in this direction are mentioned and argue that numerical investigation is a best way to make research on the internal flow of the torque convert and depending its merits ANSYS can finish this task; after that generalize the development and actuality of theory and design method of the torque convert in this part, and briefly describe several test method of the flow. Bring forward the intention and context of this dissertation at last.Theory and reason of finite element method is introduced in the second part. As an effective numerical simulation plan, FEM is more and more important in CFD and it not only is applied in linear problem, but also in non-linear problem, such as the resolve of complicated N-S equation in CFD and getting satisfactory result. For us getting a good understand of this method, the basic math method of finite element is introduced such as variation principle, Ritz method and weighted residual method. United to hydraulic torque converter, the step of this method is given. The main point of the third is the theoretical basis of CFD in ANSYS. First deduce the basic control formula of the hydrodynamics and because of the turbulence of flow in flow field, formula Renault is given and analyzes several flow models in the numerical calculation, and discuss the physical meanings of the model. In order to resolve the partial differential equation, we describe the formation of the numerical calculation and contrast several common numerical calculations and mainly several discrete methods and the basic idea of velocity-pressure coupling method and for making a further theory base for analyzing with software ANSYS, some necessary step are referred like convergence criterion and the control of convergence and stabilization.Put forward to the calculation model of the flow field and calculation condition of flow. First the regulation and the hypothesis of the torque converts flow was brought forward and predigest the flow to analyze. Then establish the three-dimension model of the impeller passage with UG soft and put the model into the girding caved up by the ANSYS. Suppose the inlet boundary of the flow way to velocity boundary condition, and suppose outlet to pressure boundary condition, and suppose other to wall boundary condition. There are many turbulence model ,discrimination methods and velocity-pressure couple methods in ANSYS. This dissertation explained all kinds of models and methods. In order to choose the best model and method, the dissertation set up many examples to contrast an...