静压气体轴承的跨尺度数值计算方法研究

发布时间：2018-07-28 11:56

【摘要】：静压气体轴承是超精密运动平台的核心部件，以其无摩擦、高速度、极高的精度等优点广泛应用于精密测量和精微加工领域，它的研究进展在一定程度上推动着相关产业的向前发展。随着超精密运动平台向着更高的精度挑战，进一步分析静压气体轴承的承载和稳定性能显得尤为重要，而气体轴承的几何结构尺寸与其气膜间隙比例达到1000:1以上，如此巨大的比例导致网格划分困难以及网格数量非常庞大，从而使得计算效率很低。因此，本文所要研究的正是针对静压气体轴承以上难点所提出的跨尺度数值计算分析方法。首先，本文介绍了静压气体轴承的工作原理和跨尺度数值计算模型，并通过联立描述流体运动的控制方程和气体状态方程推导出了气体润滑雷诺方程的一般形式。其次，给出了运用跨尺度数值计算方法计算分析无压力腔和有压力腔静压气体轴承的一般流程，同时采用该方法求出了无压力腔和有压力腔气体轴承在二维情况下的压力分布。最后，应用计算流体力学软件FLUENT计算分析了气体轴承节流孔及压力腔区域的压力分布和静态性能，同时运用有限差分法求解了描述气膜压力分布的稳态雷诺方程，且通过利用MATLAB软件求解离散化后的雷诺方程求出了气膜区域的压力分布，进而计算出气膜区域的静承载力和静刚度，将两个区域的静承载力和静刚度值加起来即组成了整个气体轴承的静态性能的值。并且将跨尺度计算结果与FLUENT仿真结果进行对比，结果表明静压气体轴承的跨尺度数值计算方法是可行的。
[Abstract]:Hydrostatic gas bearing is the core component of ultra-precision motion platform. It is widely used in precision measurement and micro-machining fields because of its advantages of non-friction, high speed, high precision and so on. Its research progress promotes the development of related industries to a certain extent. With the ultra-precision motion platform facing the challenge of higher precision, it is particularly important to further analyze the bearing capacity and stability performance of the static gas bearing, and the ratio of the geometric structure of the gas bearing to its gas film clearance is more than 1000: 1. Such a large scale makes gridding difficult and the number of meshes is very large, which makes the computing efficiency very low. Therefore, this paper is to study the above difficulties of hydrostatic gas bearings proposed by the cross-scale numerical analysis method. Firstly, this paper introduces the working principle and cross-scale numerical calculation model of hydrostatic gas bearing, and deduces the general form of gas lubricating Reynolds equation by means of the governing equation and gas state equation which describe the fluid motion simultaneously. Secondly, the general flow chart of calculating and analyzing the hydrostatic gas bearing without pressure cavity and pressure chamber by using the cross scale numerical calculation method is given, and the pressure distribution of the gas bearing without pressure chamber and pressure chamber is obtained by using this method. Finally, the pressure distribution and static performance in the throttle and pressure chamber region of the gas bearing are calculated and analyzed by the computational fluid dynamics software FLUENT, and the steady state Reynolds equation describing the gas film pressure distribution is solved by using the finite difference method. The pressure distribution in the film region is obtained by solving the discrete Reynolds equation with MATLAB software, and the static bearing capacity and stiffness of the film region are calculated. The static bearing capacity and static stiffness of the two regions are added together to form the static performance value of the whole gas bearing. The results of cross-scale calculation are compared with the results of FLUENT simulation. The results show that the cross-scale numerical method for static pressure gas bearings is feasible.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH133.36

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