Article
Engineering, Mechanical
Kazuyuki Yagi, Wataru Matsunaka, Joichi Sugimura
Summary: This study investigates the effect of textured patterns on lubrication performance in starved hydrodynamic lubrication. Longitudinal or transverse grooves on discs are found to improve lubricant supply into the lubricated area at high sliding conditions, compared to a flat disc.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Dan Li, Xuefeng Yang, Yuanbo Wu, Jian Cheng, Shouren Wang, Zhuang Wan, Wenbo Liu, Guofeng Xia
Summary: The research on surface texture is transitioning from single macro-texture to composite micro-nano texture, with a weak focus on the anti-friction mechanisms and theoretical models. Different surface texture characteristics and their applicable working conditions are the primary research focus. This study established a mathematical model for hydrodynamic lubrication, simulated four texture models, and verified the model through friction experiments, concluding that circular, chevron, groove, and composite textures have different optimal working conditions.
CHINESE JOURNAL OF MECHANICAL ENGINEERING
(2022)
Article
Engineering, Mechanical
Pengyang Li, Fan Zhang, Hao Zhang, Tianyi Wang, Quandai Wang, Weidong Qiao
Summary: New kite-shaped textures are proposed to enhance lubrication performance in hydrodynamic lubrication systems. The pressure distribution and load-carrying capacity of these textures are solved using Reynolds' equation based on mass conservation. The impact of different geometric parameters on the friction coefficient is also investigated. In addition, a double-layer composite kite-shaped texture is designed and its influence on lubrication performance is studied. Numerical simulations and experiments are conducted to identify optimal parameters and reduce friction coefficient, providing guidance for reducing frictional wear in mechanical systems under full-film oil lubrication conditions.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Qinggang Guo, Long Zheng, Yinghui Zhong, Shukun Wang, Luquan Ren
Summary: Numerical models of continuous groove textures with X-shaped units were established in this study. The effects of geometric parameters and sliding speed on tribological properties were systematically investigated. The optimal geometric parameters for each texture shape were determined. It was found that the circular texture exhibited the best lubrication performance at lower area densities, while the square texture with a groove depth increase and an orientation of theta = 90 degrees showed better tribological performance when the area density exceeded 25%. The lubrication mechanism was explained as a trade-off between fluid flow and the generation of hydrodynamic pressure.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Mert Yusuf Cam, Matteo Giacopini, Daniele Dini, Luca Biancofiore
Summary: Hydrodynamic lubrication plays a fundamental role in mechanical systems by reducing energy losses and preventing mechanical breakdown. The classical linear Reynolds equation is insufficient for describing the lubricant characteristics on engineered surfaces, and non-linearities introduced by wall slip and cavitation need to be considered. Therefore, a modified two-dimensional Reynolds equation is proposed to capture both the cavitation presence and wall slippage, leading to improved accuracy and computational efficiency.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Mechanics
Fangrui Lv, Yanqin Shangguan, Donglin Zou, Aimin Ji
Summary: This study proposes a transient mixed-lubrication model considering turbulence to investigate the dynamic characteristics of mixed-lubricated bearings. The effects of turbulence, surface roughness, and impact load direction on transient lubrication are analyzed based on a derived transient Reynolds equation and the journal's dynamic equation.
Article
Engineering, Mechanical
Maximillian Zimmer, Sorin-Cristian Vladescu, Lars Mattsson, Mark Fowell, Tom Reddyhoff
Summary: Based on experiments with reciprocating rig, it was found that macro-scale surface texture can reduce friction by up to 35% in the hydrodynamic regime. The Shear-Area Variation mechanism suggests that macro-texture can reduce contact area and increase shear-rate, leading to reduced friction and potential efficiency improvements in machines.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
S. S. Gamaniel, D. Dini, L. Biancofiore
Summary: This work investigates the influence of fluid viscoelasticity on the performance of lubricated contacts in the presence of cavitation. The study uses the Oldroyd-B model to describe the effect of viscoelasticity and linearizes the equations to analyze the impact of viscoelastic thin films under cavitation conditions.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
He Li, Junkai Niu
Summary: This paper investigates the impact of texture on the tribological performance of journal bearings operating under starvation lubrication conditions. The P-theta model with mass conservation boundary conditions accurately predicts the oil film distribution in the full oil film/starvation region of the textured bearing. The study discusses the effects of different levels of starvation lubrication on parameters such as eccentricity, attitude angle, full film area, and friction coefficient in textured bearings. The results show that the severity of the texture's effect on bearing performance varies with starvation levels and that texturing can improve the bearing's operating performance, increase load carrying capacity, reduce friction coefficient, and enhance safety.
SURFACE TOPOGRAPHY-METROLOGY AND PROPERTIES
(2023)
Article
Physics, Multidisciplinary
M. S. Faltas, H. H. Sherief, Nasser M. El-Maghraby, E. F. Wanas
Summary: A semi-analytical model has been developed to analyze the rectilinear oscillations of a spherical particle immersed in an incompressible micropolar fluid bounded by a rigid plane wall. The study shows that the presence of the bounding wall and micropolarity and slip parameters have significant effects on the drag coefficients.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Engineering, Mechanical
Xuefeng Chang, Duoji Renqing, Longxing Liao, Peiyuan Zhu, Bingjing Lin, Yubin Huang, Shanming Luo
Summary: This paper investigates the impact of groove-type tooth surface texture on wear and adhesion in spur gear transmission. The core size parameters of the groove texture are optimized through experiments and simulations, showing that the groove texture can significantly reduce friction wear and adhesion, thereby improving the gear transmission life.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Zihan Shen, Fengchao Wang, Zhiguo Chen, Xiaopeng Ruan, Hanghang Zeng, Jiahui Wang, Yurong An, Xiaoli Fan
Summary: Numerical simulations were used to study the lubrication performance of chevron textured surfaces under hydrodynamic lubrication. It was found that the V-shape arrangement of chevron textures greatly improved lubrication performance, providing an effective way to enhance the load carrying capacity and reduce friction coefficient on such surfaces.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Fankeng Zeng, Yu Cheng, Zhenping Wan, Zhineng Long, Zhihui Zhang, Yong Tang
Summary: A novel compound texture consisting of circular concave and spherical convex was proposed to improve the tribological performance under hydrodynamic lubrication. Numerical modeling and experimental results showed that the spherical convex enhanced lubricant suction and generated second hydrodynamic lubrication, resulting in improved load-bearing capacity compared to the optimal circular concave texture.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Huanhuan Wang, Naiming Lin, Shuo Yuan, Zhiqi Liu, Yuan Yu, Qunfeng Zeng, Dongyang Li, Jianfeng Fan, Yucheng Wu
Summary: Inspired by natural shell surfaces, six bionic multi-scale composite surface textures were designed and numerically simulated to investigate their influence on lubrication characteristics. The results showed that the bionic surface enhanced load-carrying capacity and reduced friction coefficient. Groove combinations had better lubrication performance compared to wavy combinations. The texture geometric parameters significantly affected the frictional characteristics.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Wei Feng, Yanfeng Han, Guo Xiang, Jiaxu Wang
Summary: Among three different microgroove distributions of Partial Microgroove Water-lubricated Bearings (PMWB), herringbone-groove bearings have the highest load capacity, followed by spiral-groove bearings and straight-groove bearings. Wall slip is shown to enhance the load capacity for all three types of microgroove distributions. The parametric study reveals that the eccentricity ratio significantly affects the lubrication performance of PMWB, while the groove depth and angle have minor effects.
SURFACE TOPOGRAPHY-METROLOGY AND PROPERTIES
(2021)
