移动副速度对空气轴承影响的CFD仿真分析

Simulation of Relationship Beteen Velocity of Bearing's Moving Pad and Characteristics of Air Bearing with Orifice Array

研究空气轴承优化控制问题,针对高速移动副空气轴承对空气轴承气膜特性会影响定位精度特点,空气轴承采用非结构化网格实现了多节流器气膜的耦合,设计的密度可控的非均匀网格划分方案克服了最大最小尺寸比偏大给实际带来的困难。根据FLUENT用三维双精度耦合隐式标准k-ε粘性湍流两方程模型,仿真得到了不同移动副速度时,阵列多节流器耦合后的质量流量、气膜压强分布和速度分布,为辨识高速移动副时多节流器耦合的气膜数学模型提供了详实数据。当增大移动副速度时,耗气量减小但气膜承载力增加,为高速移动副空气轴承的优化设计提供了依据。

Moving pad velocity＇ s influence on film properties was analysed, which is the critical issue of development of high speed moving pad air bearing. Unstructured grids were used to achieve coupling effect of gas from many restrictors in 4×4 orifices array. The difficulties, from larger ratio of maximum size to minimum size, were overcomed by non-uniform meshing methods. Base on FLUENT, a 3d dp CFD solver was analyzed, using coupled implicit tur- bulence model called standard k-ε with two equations, and the mass flux, pressure distribution and velocity distribution of the air films were obtained in different velocity of moving pad, preparing for the identification of films＇ mathematical model. Simulation results indicate that the average air film pressure and carrying capacity increase in a certain range with the increasing of moving pad velocity, and the total mass flux decreases similarly. The conclusion provides a basis for optimal design of air bearing with high speed moving pad.