摘要
为了揭示凹槽内部剪切流动特性对滑动减阻效果的影响,利用静、动滑动摩擦因数测试系统和计算流体力学方法,理论、实验和数值模拟研究了凹槽高宽比(e=0.5、1.0、2.0、3.0)、凹槽几何尺寸、壁面运动速度等因素,对凹槽内的剪切流动特性及壁面滑动减阻效果的影响.研究发现,凹槽结构增加了润滑油滑动减阻效果,凹槽几何结构对减阻效果有明显影响,当凹槽宽度L、深度H均为2 mm时,凹槽的减阻效果相对较好,且壁面运动速度对其剪切力减小率fτ的影响较小.此外,凹槽尺寸、壁面滑动速度对凹槽内流场特性有重要影响,不同工况下凹槽内部存在上下2个涡或者1个大涡和2个边角涡.结果表明:凹槽内的剪切流动特性对滑动减阻效果有重要影响,并可为滑块表面凹槽结构设计提供重要的指导.
To reveal the effects of shear flow behaviors in grooves on the reduction efficiency of sliding resistance, theoretical analysis, experiments and numerical simulation were carried out using a static/ dynamic sliding friction coefficient test system and computational fluid dynamic （CFD） method. The influence of groove sizes （ aspect ratio of 0. 5,1,2 ,and 3） and the velocity of sliding wall on the shear flow characteristics in grooves and the drag reduction efficiency of the sliding wall were investigated. It is found that the surface groove increases the drag reduction effect of lubrication oil, and the groove structure has significant influence on the drag reduction effect. When the width and depth are 2 mm,the groove has better drag reduction effect, and the wall sliding speed has low influence on the wall shear stress distribution. Moreover,the groove size and the wall sliding speed have important influence on the characteristics of the flow field in the groove. Under different working conditions,there are two or one large vortex and two corner vortexes in the groove. Results show that the shear flow behaviors in the groove have significant influences on the drag reduction effect,and can provide a useful guidance for the design of the groove for drag reduction.
出处
《北京工业大学学报》
CAS
CSCD
北大核心
2018年第2期161-169,共9页
Journal of Beijing University of Technology
基金
北京市自然科学基金资助项目(7152012)
北京市教育委员会科技计划项目(KM201610005002)
北京工业大学"日新人才"培养计划项目(2015-RX-L02)
关键词
表面凹槽
剪切流动
减阻
滑动阻力
surface groove
shear flow
drag reduction
sliding resistance
