Simulation Based On FLUENT And Experimental Research Of Porous Aerostatic Bearing

Aerostatic bearings have been applied widely on the ultra-precision in the aviation, aerospace and the main axes and the slide of the precision measuring instrument and inertial measuring apparatus because of high rotation accuracy, calm operation, low friction and long life-span etc. They can also be used in fields range from both high and low temperature to both high and low velocity, sometime even to environment full of radioelement. People now pay much attention at porous aerostatic bearing which has obviously higher load capacity and better damping characteristic and stability. There are two kinds of porous aerostatic bearing: the whole porous and partial porous. This paper does a research on the static characteristic of both the two kinds of porous bearings on the base of theory analysis, simulation method and experimental investigation.First of all, the mathematical model and theoretical formula of static characteristic for both whole and partial porous bearings are presented. The solutions are also given.Then this thesis apply iterative computation using Fluent software, that means FLUENT is successfully used in the research of porous aerostatic bearing field for the first time. FLUENT is based on Finite volume method, which is different form the widely used traditional analytical solution and numerical method based on Finite element method and Finite difference method, and its advantage is the high computational efficiency and precision. On the other hand, this software has strict requirement of boundary condition, calculation model, control parameters and the mesh quality, and it's rarely used in this area which add the difficulty of application. In this paper, the pressure field and static characteristic of bearings are simulated by FLUENT. The pressure contours of restrictors and shaft are acquired as well as the load capacity and static stiffness curves versus eccentricity ratio. For the whole porous bearing, the data and curves are acquired, such as, the load capacity and static stiffness versus the supply pressure, permeability, thickness of the film, eccentricity ratio and the structure parameters of the bearing. What's more, some disciplinary conclusions are drawn.