Numerical analysis and optimization of rectangular texture for gas foil thrust bearing

2020 ◽  
Vol 235 (8) ◽  
pp. 1599-1613
Author(s):  
Zhenpeng He ◽  
Chun Zhang ◽  
Jianqiang Li ◽  
Yuanyuan Zhao ◽  
Aijun Sun
Keyword(s):  
Surface Texture ◽  
Texture Parameters ◽  
Lubrication Performance ◽  
Foil Thrust Bearing ◽  
The Stability ◽  
Texture Size ◽  
Rectangular Groove ◽  
Radial Arrangement ◽  
Texture Design ◽  
Oil Film Pressure

Accurate surface texture design is of great significance to improve the performances of gas bearings. In this article, the finite difference method and Newton’s method were combined to obtain the oil film pressure distribution, and the effect of rectangular groove on the lubrication performance was analyzed by changing representative texture parameters. The results show that the performances were more affected by the rectangular texture size compared with the distribution and the bottom shape of texture. The increasing of the surface texture number can only enhance the stability of the bearing. The bearing can provide 30% more bearing capacity by choosing larger size, radial arrangement and plane bottom. These results and analysis can provide technical reference for the bearing texture design.

scholarly journals Enhancing Full-Film Lubrication Performance Via Arbitrary Surface Texture Design

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Yong Hoon Lee ◽  
Jonathon K. Schuh ◽  
Randy H. Ewoldt ◽  
James T. Allison
Keyword(s):  
Surface Texture ◽  
Performance Metrics ◽  
Optimization Problems ◽  
Spline Interpolation ◽  
Load Capacity ◽  
Improve Performance ◽  
Disk Radius ◽  
Lubrication Performance ◽  
Texture Design ◽  
Film Lubrication

Minimizing energy loss and improving system load capacity and compactness are important objectives for fluid power systems. Recent studies reveal that microtextured surfaces can reduce friction in full-film lubrication, and that asymmetric textures can reduce friction and increase normal force simultaneously. As an extension of these previous discoveries, we explore how enhanced texture design can maximize these objectives together. We design surface texture using a set of distinct parameterizations, ranging from simple to complex, to improve performance beyond what is possible for previously investigated texture geometries. Here, we consider a rotational tribo-rheometer configuration with a fixed textured bottom disk and a rotating top flat disk with controlled separation gap. To model Newtonian fluid flow, the Reynolds equation is formulated in cylindrical coordinates and solved using a pseudospectral method. Model assumptions include incompressibility, steady flow, constant viscosity, and a small gap height to disk radius ratio. Multi-objective optimization problems are solved using the epsilon-constraint method along with an interior-point (IP) nonlinear programming algorithm. The trade-off between competing objectives is quantified, revealing mechanisms of performance enhancement. Various geometries are explored and optimized, including symmetric and asymmetric circular dimples, and novel arbitrary continuous texture geometries represented using two-dimensional cubic spline interpolation. Shifting from simple dimpled textures to more general texture geometries resulted in significant simultaneous improvement in both performance metrics for full-film lubrication texture design. An important qualitative result is that textures resembling a spiral blade tend to improve performance for rotating contacts.

An improved TEHL analysis of textured roller bearings consider various texture parameters and slip

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junning Li ◽  
Ka Han ◽  
Wuge Chen ◽  
Xiaojie Tang ◽  
Qian Wang
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Contact Area ◽  
Surface Texturing ◽  
Elastohydrodynamic Lubrication ◽  
Content Type ◽  
Roller Bearings ◽  
Texture Parameters ◽  
Lubrication Performance ◽  
Texture Size

Purpose The purpose of this study is to reveal the lubrication performance of textured roller bearings under various texture size, texture depth, texture types and slip. Design/methodology/approach In the present study, the improved thermal elastohydrodynamic lubrication method based on the surface texturing of the textured roller bearings is proposed, and then the effect of texture size, texture depth, texture types and slip on the contact pressure, film thickness and temperature distribution are analyzed systematically. Findings The results show that the pressure decreases and the film thickness increases on the contact area because of the surface texturing. The temperature increases first and then decreases as the texture size increases, and then the temperature increases as the texture depth and the slip increases. Compared to circle and square texture, cross texture can obviously decrease the temperature on the contact area. The effectiveness of the proposed method is verified. Originality/value This study can help to reduce friction and wear of textured roller bearings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2020-0318/

scholarly journals Characterization of the surface of formworks – Influence of the surface energy and surface texture parameters on the demolding forces

2021 ◽  
Vol 272 ◽  
pp. 121947
Author(s):  
Calypso Chadfeau ◽  
Safiullah Omary ◽  
Essia Belhaj ◽  
Christophe Fond ◽  
Françoise Feugeas
Keyword(s):  
Surface Energy ◽  
Surface Texture ◽  
Texture Parameters

scholarly journals Analysis of High-Friction Surface Texture with Respect to Friction and Wear

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 758
Author(s):  
Cibi Pranav ◽  
Minh-Tan Do ◽  
Yi-Chang Tsai
Keyword(s):  
Friction Coefficient ◽  
Surface Texture ◽  
Safety Concern ◽  
Future Research ◽  
Scanning System ◽  
Novel Approach ◽  
Texture Parameters ◽  
Aggregate Loss ◽  
Friction Surfaces ◽  
The Impact

High Friction Surfaces (HFS) are applied to increase friction capacity on critical roadway sections, such as horizontal curves. HFS friction deterioration on these sections is a safety concern. This study deals with characterization of the aggregate loss, one of the main failure mechanisms of HFS, using texture parameters to study its relationship with friction. Tests are conducted on selected HFS spots with different aggregate loss severity levels at the National Center for Asphalt Technology (NCAT) Test Track. Friction tests are performed using a Dynamic Friction Tester (DFT). The surface texture is measured by means of a high-resolution 3D pavement scanning system (0.025 mm vertical resolution). Texture data are processed and analyzed by means of the MountainsMap software. The correlations between the DFT friction coefficient and the texture parameters confirm the impact of change in aggregates’ characteristics (including height, shape, and material volume) on friction. A novel approach to detect the HFS friction coefficient transition based on aggregate loss, inspired by previous works on the tribology of coatings, is proposed. Using the proposed approach, preliminary outcomes show it is possible to observe the rapid friction coefficient transition, similar to observations at NCAT. Perspectives for future research are presented and discussed.

Numerical and experimental study on the effect of surface texture with roughness orientation considered under a mixed lubrication state

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junru Wang ◽  
Quandai Wang ◽  
Yueyan Li ◽  
Meiling Guo ◽  
Pengyang Li ◽  
...  
Keyword(s):  
Surface Texture ◽  
Surface Texturing ◽  
Mixed Lubrication ◽  
Laser Surface ◽  
Geometric Parameters ◽  
Laser Surface Texturing ◽  
Textured Surface ◽  
Asperity Contact ◽  
Content Type ◽  
Texture Parameters

Purpose The purpose of this paper is to investigate the effects of surface texture with roughness orientation considered on tribological properties under a mixed lubrication state numerically and experimentally. Design/methodology/approach Based on the average Reynolds equation and asperity contact model, the impacts of surface texture parameters and roughness orientation on lubrication properties have been calculated using finite difference method. Tin–bronze samples with various prescribed surface texture geometric parameters and roughness orientation were fabricated by laser surface texturing technique, and the tribology performance of the textured surface was studied experimentally. Findings The effects of surface geometric parameters and roughness orientation parameters have been discerned. The experimental observations are in good agreement with the numerical prediction, which suggests that the numerical scheme adopted in this work is suitable in capturing the surface texture and roughness effect under mixed lubrication state. Originality/value By meticulously controlling the surface roughness and surface texture geometric characteristics based on the laser surface texturing process, samples with prescribed surface texture parameters and roughness orientation consistent with that in theoretical studies were fabricated and the theoretical model and results were verified experimentally.

Estimation of Service Life of Mechanical Engineering Components

2019 ◽  
Vol 799 ◽  
pp. 71-76
Author(s):  
Oskars Linins ◽  
Ernests Jansons ◽  
Armands Leitans ◽  
Irina Boiko ◽  
Janis Lungevics
Keyword(s):  
Service Life ◽  
Service Time ◽  
Surface Texture ◽  
Mechanical Engineering ◽  
Friction Pair ◽  
Theory Of Elasticity ◽  
New Approach ◽  
Material Fatigue ◽  
Texture Parameters ◽  
3D Surface Texture

The paper is aimed to the methodology for estimation of service life of mechanical engineering components in the case of elastic-plastic contact of surfaces. Well-known calculation methods depending on physics, theory of probability, the analysis of friction pair’ shape and fit include a number of parameters that are difficult or even impossible to be technologically controlled in the manufacturing of mechanical engineering components. The new approach for wear rate estimation using surface texture parameters as well as physical-mechanical properties and geometric parameters of components is proposed. The theoretical part of the calculations is based on the 3D surface texture principles, the basics of material fatigue theory, the theory of elasticity and the contact mechanics of surfaces. It is possible to calculate the service time of the machine, but the process of running-in of the components is relatively short (less than 5%), therefore, the service time is mainly determined by a normal operating period, which also was used to evaluate this period. The calculated input parameters are technologically and metrologically available and new method for calculating the service time can be used in the design process of the equipment. The results of approbation of the method for estimation service time of mechanical engineering, which prove the applicability of mentioned method, are offered as well.

Automated Gaging of Surface Texture on Engine Components

2015 ◽  
Author(s):  
Turker Oktay
Keyword(s):  
Surface Texture ◽  
Combustion Engine ◽  
Surface Preparation ◽  
Target Surface ◽  
Operating Life ◽  
Design Engineers ◽  
Texture Parameters ◽  
Repeatability And Reproducibility ◽  
Engine Components ◽  
Selection Of

Surface texture of engine components such as crankshafts and camshafts is one of the most important factors that determine the performance, efficiency and the operating life of an internal combustion engine. Current practices and the challenges faced by design engineers in specifying the target surface topography to meet these goals have been reviewed. Once specified, the surface texture must be measured fast, accurately and repeatably in the rough environment of an engine manufacturing plant. The key components of an automated skidded surface finish measuring gage designed with these criteria in mind are described in this paper. The gage has 7 axes of motion and 3 stylus probes oriented in the axial and radial directions to take axial and facial measurements on journal and cam lobe surfaces and thrust bearing surfaces. The selection of surface texture parameters to best describe the desired surface texture of these engine components was investigated. The final stage of surface preparation is often the superfinishing process. The measurement gage must be able to provide the sensitivity and repeatability that are required for measuring the finely finished surfaces generated by this process. Typical surface texture results of a superfinishing process achieved on crankshafts are described. The results of a Gage Repeatability and Reproducibility (R&R) study performed on the surface texture measuring gage are presented.

scholarly journals Surface Texture Design and Its Tribological Application

2019 ◽  
Vol 55 (17) ◽  
pp. 85 ◽  
Author(s):  
ZHANG Hui ◽  
LIU Yang ◽  
WANG Wei ◽  
QIN Liguo ◽  
DONG Guangneng
Keyword(s):  
Surface Texture ◽  
Tribological Application ◽  
Texture Design

scholarly journals Functional Importance of Surface Texture Parameters

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5326
Author(s):  
Pawel Pawlus ◽  
Rafal Reizer ◽  
Michal Wieczorowski
Keyword(s):  
Literature Review ◽  
Surface Topography ◽  
Surface Texture ◽  
3D Analysis ◽  
Functional Importance ◽  
Hybrid Functional ◽  
Functional Feature ◽  
Texture Parameters ◽  
Future Challenges ◽  
Selection Of

Areal 3D analysis of surface texture gives more opportunities than a study of 2D profiles. Surface topography evaluation, considered as 3D dimensional analysis in micro or nanoscales, plays an important role in many fields of science and life. Among many texture parameters, those connected with height are the most often used. However, there are many other parameters and functions that can provide additional important information regarding functional behaviour of surfaces in different applications. The knowledge about the functional importance of various surface properties is low. This review tries to fill this gap. Surface texture parameters are presented in various groups: height, spatial, hybrid, functional, feature, and others. Based on experiences of the present authors and literature review, the relationships among various surface parameters and functional properties are described. A proposal of a selection of parameters on the basis of their functional significations is provided. Considerations for future challenges are addressed.

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