摘要
针对液压系统中微米级油膜缝隙流动内的近壁面滑移微观尺度效应,采用计算流体力学(Computational fluid dynamics,CFD)方法分析壁面滑移作用对微米级油膜缝隙流动规律特性的影响。在对静压支承系统中封油边内油膜缝隙流动进行边界条件处理时,采取了壁面滑移速度与壁面滑移系数和当地局部速度梯度都成正比的Navier滑移模型边界条件。在数值模拟和理论基本吻合的基础上,进一步讨论分析壁面滑移系数对微米级油膜缝隙流动特性的影响,侧重分析考虑壁面表观粘度系数、温粘特性和非牛顿流体属性对微米级油膜缝隙流动特性分布和缝隙壁面滑移速度大小的影响。研究表明在微观尺度下具有界面滑移的油膜缝隙流动区别于无滑移的缝隙流动特性,壁面材料特性系数φ=0.01时,缝隙壁面的滑移速度越大,油膜缝隙流动分布均匀。其温粘特性将最大限度地影响壁面滑移速度大小和缝隙流动特性分布。
For micro effect of the slippage phenomenon adjacent to wall in micro-scale gap flow of hydraulic system,computational fluid dynamics（CFD） method is applied to investigate the effects of wall slip on flow behaviors in micro-scale gap.The Navier slip boundary condition,which wall slip velocity is proportional to the degree of slip coefficient and the local velocity gradient,is adopted to simulate the gap flow between oil sealing sides in hydrostatic bearing system.After examining consistency of results between simulation and theory,the influence of slip parameter on gap flow behavior is implemented.The influence of wall apparent viscosity coefficient,temperature-viscosity characteristic and Non-Newtonian behavior on distributions of flow in gap and the value of wall slip velocity are analyzed deeply.It is shown that micro-scale gap flow with slip condition is different from that of no-slip boundary condition,when the wall material property coefficient ？ =0.01,the faster of the wall slip velocity and more uniform of velocity in flow gap,and the temperature-viscosity characteristic is the significant factor affecting gap flow distribution and slip velocity.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2011年第21期104-110,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(11072011
11002007)
