摘要
针对液体静压转台在承受偏载运行时,转台上下导轨面易发生刮擦的现象,为解决传统解析计算方法难以建立偏载静压转台转动状态下承载力及倾覆力矩数学模型,且传统CFD计算方法无法实现对几何边界运动变化的流体域进行建模计算的难题,提出偏载液体静压转台旋转工况下承载力及倾覆力矩动网格计算方法。该方法采用自定义程序实现对静压转台旋转时油膜形态变化的控制;利用弹簧光顺模型更新因转台倾斜方向改变引起的油膜网格变形;将油膜旋转动边界转换为静止边界,有效避免转台旋转引起的网格畸变。采用该方法进行计算,能利用同一模型实现对不同油膜厚度、不同倾斜位移率的油膜进行仿真,避免重复建模,提高了计算效率;能形象再现油膜三维流场压力分布的动态变化过程,计算结果体现了转台运动对流场分布的影响,更贴近工程实际。利用所提出的方法对国产某典型静压转台的承载力及倾覆力矩进行计算,并建立静压转台试验系统,对偏载静压转台进行试验研究。试验数据与动网格方法计算结果的对比分析表明,两者基本吻合,证实所提出的偏载液体静压转台旋转工况下承载力及倾覆力矩动网格计算方法有效。
The hydrostatic rotary table’s upper and lower guides are prone to scratch each other when the partial loaded hydrostatic rotary table is rotating. In the former study of this phenomenon, it is hard to establish a practical mathematical model of carrying capacity and overturning moment of the hydrostatic rotary table based on traditional analytical calculating method, and the modeling and calculating of fluid domain with a changing geometrical boundary can not be conducted when utilizing the traditional CFD simulation method. To solve this problem, a new calculation method based on dynamic mesh model is proposed, which is used to calculate the bearing capacity and overturning moment of the partial loaded hydrostatic rotary table under rotating condition in engineering practice. The change of oil film form is controlled by using user definition function. Deformation of oil film mesh caused by the changing of rotary table’s tilting direction is refreshed using spring smoothing theoretical model. The oil film’s moving boundary caused by rotational movement is changed into static boundary for avoiding the grid distortion. This method can realize the simulation of oil film with different thickness and tilt displacement rate using the same model, which can avoid the repeatedly building of calculating model and improving the computational efficiency. The dynamic process of three dimensional pressure distribution of oil film is reappeared. The impact of rotary table’s motion on flow field distribution can be reflected in the calculating result which is closer to engineering practice. The bearing capacity and overturning moment of a typical hydrostatic rotary table are calculated by using the proposed method and the experiment of hydrostatic rotary table bearing partial load is conducted. The experimental results are in reasonable agreement with calculation ones, which have verified the effectiveness of the proposed calculating method.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2014年第23期66-74,共9页
Journal of Mechanical Engineering
基金
国家自然科学基金(51275163)
湖南省自然科学杰出青年基金(12JJ1006)资助项目
关键词
液体静压转台
偏载
动网格
承载力
倾覆力矩
hydrostatic rotary table
partial load
dynamic mesh
bearing capacity
overturning moment
