Comparison of Homogenization and Direct Techniques for the Treatment of Roughness in Incompressible Lubrication

Kane, Malal; Said, Benyebka Bou

doi:10.1115/1.1792699

Cited by 44 publications

(17 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The modeling of the fluid flow problem in mixed lubrication has been addressed by Bayada [164][165][166][167][168], Jai and Bou-Saïd [169][170][171] and Buscaglia [172][173][174] within the framework of the homogenization theory for spatially periodic roughness. This approach is based upon the derivation of a homogenized Reynolds equation, defined at the macroscopic global scale, which captures the overall effects of the surface roughness on the lubricant flow.…”

Section: Homogenization Methodsmentioning

confidence: 99%

Multi-Scale Surface Texturing in Tribology—Current Knowledge and Future Perspectives

2019

View full text Add to dashboard Cite

Surface texturing has been frequently used for tribological purposes in the last three decades due to its great potential to reduce friction and wear. Although biological systems advocate the use of hierarchical, multi-scale surface textures, most of the published experimental and numerical works have mainly addressed effects induced by single-scale surface textures. Therefore, it can be assumed that the potential of multi-scale surface texturing to further optimize friction and wear is underexplored. The aim of this review article is to shed some light on the current knowledge in the field of multi-scale surface textures applied to tribological systems from an experimental and numerical point of view. Initially, fabrication techniques with their respective advantages and disadvantages regarding the ability to create multi-scale surface textures are summarized. Afterwards, the existing state-of-the-art regarding experimental work performed to explore the potential, as well as the underlying effects of multi-scale textures under dry and lubricated conditions, is presented. Subsequently, numerical approaches to predict the behavior of multi-scale surface texturing under lubricated conditions are elucidated. Finally, the existing knowledge and hypotheses about the underlying driven mechanisms responsible for the improved tribological performance of multi-scale textures are summarized, and future trends in this research direction are emphasized.

show abstract

Section: Homogenization Methodsmentioning

confidence: 99%

Multi-Scale Surface Texturing in Tribology—Current Knowledge and Future Perspectives

2019

View full text Add to dashboard Cite

show abstract

“…Such simulations have been applied to both compressible and incompressible flows, to Newtonian and non-Newtonian fluids, but only for laminar flow. [5][6][7][8] In all these studies, and in the present study, the perturbation method is used with the inverse number of roughness peaks as the small parameter. Perturbation methods have inherent limitations, in which the influence of the perturbing effect on the base flow (i.e., the smooth case) must be small.…”

Section: Homogenization Methodsmentioning

confidence: 99%

The homogenization method of roughness analysis in turbulent lubrication

Lahmar

Bou‐Saïd

Tichy

2013

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

The hydrodynamic lubrication theory founded by Osborne Reynolds in 1886 is based on several assumptions, including that the contact surfaces are perfectly smooth, and the lubricant flow regime is laminar. However, in certain special cases these hypotheses may not be valid, and it is seen that surface roughness and turbulence affect bearing performance. The approach adopted in the present work is based on the application of the homogenization method to the turbulent Reynolds equation. In homogenization, multiscale expansion of the fluid pressure terms leads to a system of four partial differential equations governing two types of problems (local and global). The solutions are, respectively, periodic functions, and the homogenized pressure. As an illustrative example, a journal bearing with a rough surface operating in the turbulent regime is analyzed. Numerical simulations are performed by imposing periodic isotropic roughness patterns over the stationary outer cylinder surface. The homogenized solutions are compared to direct solutions of the deterministic problem. Homogenization is shown to be a powerful but practical method to attack problems of rough surfaces and is applied to turbulent lubrication for the first time. In the plain journal bearing example, the effect of roughness is to increase the load significantly in many cases. The effect of turbulence is to greatly increase the load, in both the rough and smooth cases.

show abstract

Section: Introductionmentioning

confidence: 99%

“…To incorporate the effect of surface roughness without resolving the surfaces, an averaged Reynolds equation is often used to solve for the averaged fluid pressure (see, eg, other works [3][4][5][6][7]. In the works of Jai and Bou-Saïd 8 and Kane and Bou-Saïd, 9 it is shown that significantly fewer degrees of freedom are required for solving the homogenized equations compared to the direct equations in order to obtain the pressure field between rough surfaces. A framework to consider the effects of deformation of structural bodies interacting via a thin fluid film was presented in the works of Yang and Laursen 10 and Budt et al 11 A comparison of numerical solutions for the full spatially discretized fluid momentum and continuity equations and the Reynolds approach, tested for a problem setup with valid thin-film approximation presented in the work of Almqvist et al, 12 shows that there is no significant deviation of the results between both approaches.…”

Section: Introductionmentioning

confidence: 99%

A consistent approach for fluid‐structure‐contact interaction based on a porous flow model for rough surface contact

Ager

Schott

Vuong

et al. 2019

Numerical Meth Engineering

View full text Add to dashboard Cite

Summary Simulation approaches for fluid‐structure‐contact interaction, especially if requested to be consistent even down to the real contact scenarios, belong to the most challenging and still unsolved problems in computational mechanics. The main challenges are 2‐fold—one is to have a correct physical model for this scenario, and the other is to have a numerical method that is capable of working and being consistent down to a zero gap. Moreover, when analyzing such challenging setups of fluid‐structure interaction, which include contact of submersed solid components, it gets obvious that the influence of surface roughness effects is essential for a physical consistent modeling of such configurations. To capture this system behavior, we present a continuum mechanical model that is able to include the effects of the surface microstructure in a fluid‐structure‐contact interaction framework. An averaged representation for the mixture of fluid and solid on the rough surfaces, which is of major interest for the macroscopic response of such a system, is introduced therein. The inherent coupling of the macroscopic fluid flow and the flow inside the rough surfaces, the stress exchange of all contacting solid bodies involved, and the interaction between fluid and solid are included in the construction of the model. Although the physical model is not restricted to finite element–based methods, a numerical approach with its core based on the cut finite element method, enabling topological changes of the fluid domain to solve the presented model numerically, is introduced. Such a cut finite element method–based approach is able to deal with the numerical challenges mentioned above. Different test cases give a perspective toward the potential capabilities of the presented physical model and numerical approach.

show abstract

Comparison of Homogenization and Direct Techniques for the Treatment of Roughness in Incompressible Lubrication

Cited by 44 publications

References 22 publications

Multi-Scale Surface Texturing in Tribology—Current Knowledge and Future Perspectives

Multi-Scale Surface Texturing in Tribology—Current Knowledge and Future Perspectives

The homogenization method of roughness analysis in turbulent lubrication

A consistent approach for fluid‐structure‐contact interaction based on a porous flow model for rough surface contact

Contact Info

Product

Resources

About