An adaptive finite element procedure for fully-coupled point contact elastohydrodynamic lubrication problems

Ahmed, Sarfraz; Goodyer, Christopher E.; Jimack, Peter K.

doi:10.1016/j.cma.2014.08.026

Cited by 14 publications

(9 citation statements)

References 41 publications

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“…This results have a good agreement with that results presented by Ranger A.P, et al [17]. This represents the characteristic feature for the isoviscous elasto-hydrodynamic regime [18,19].…”

Section: Resultssupporting

confidence: 92%

Effect of Oil Temperature on Load Capacity and Friction Power Loss in Point Contact Elasto-hydrodynamic Lubrication

Fatehallah

Hammoudi

Zidane

2019

NJES

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This study presents a numerical analysis for point contact Elasto-hydrodynamic lubrication EHL. The oils used are (0W-30 and 10W-40) as lubricants. The pressure and film-thickness profiles for point contact EHL are evaluated. The aims of this study are to estimate the effect of oil’s temperature on friction force, coefficient of friction and load carrying capacity. By using FORTRAN program, the Forward-iterative method is used, to solve two dimensional (2D) EHL problem. The viscosity is updating in the solution by using Roeland’s model. After the convergence of pressure is done, the friction force, friction power losses, and friction coefficient are calculated. The temperature used ranges from (-20 to 120 oC). The results showed the film-thickness decreases with the increasing of temperature. Though the maximum pressure is not affected, only the pressure distribution and profile are changed, inlet pressure decreases and the pressure profile tends towards a hertzian (dry contact) one. The friction force and the coefficient of friction decrease with the increasing of temperature.

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“…This results have a good agreement with that results presented by Ranger A.P, et al [17]. This represents the characteristic feature for the isoviscous elasto-hydrodynamic regime [18,19].…”

Section: Resultssupporting

confidence: 92%

Effect of Oil Temperature on Load Capacity and Friction Power Loss in Point Contact Elasto-hydrodynamic Lubrication

Fatehallah

Hammoudi

Zidane

2019

NJES

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“…The first class are algorithms conceived to efficiently solve the details of the problem, including the small-scale behavior. Examples of these methods applied to solve tribological problems are the multi-grid [208][209][210][211][212][213] and adaptive mesh refinements [214][215][216][217][218] methods. In fact, these are linear scaling algorithms, which implies that their computational complexity scales linearly with the number of degrees of freedom necessary to represent the detailed micro-scale solution.…”

Section: Numerical Multi-scale Modelingmentioning

confidence: 99%

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

2019

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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.

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“…Three values of the load capacity W L = 100, 125, 150 kN/m were selected to demonstrate the response over a range of conditions, these loads represent a lightly loaded contact in which good convergence was achieved. For high loads a more stable solution procedure than that used here would be suitable, such Habchi et al [40] or Ahmed et al [41], these methods would need to be combined with flow factors introduced here in order to incorporate micro-EHL effects.…”

Section: Geometry and Operating Conditions 331 Macro-scale Conditionsmentioning

confidence: 99%

“…Habchi et al [40] or Ahmed et al [41], the HMM method will also be furthered to include out-of-plane lubricant flow in the macro-scale and to model the interaction of two rough deformable surfaces in contact. …”

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confidence: 99%

Heterogeneous Multiscale Methods for modelling surface topography in Elastohydrodynamic Lubrication line contacts

Boer

Gao

Hewson

et al. 2017

Tribology International

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A multiscale method for the Elastohydrodynamic Lubrication (EHL) of line contacts is derived based on the Heterogeneous Multiscale Methods. Periodicity applies to the topographical features and lubricant flow, data is homogenised over a range of variables at a micro-scale and coupled into a macro-scale model. This is achieved using flow factors as calculated from metamodels, which themselves evolve with the solution procedure. Results are given for an idealised topography and illustrate significant deviations from smooth surface assumptions as quantified by the flow factors. Improvements in the accuracy and efficiency with previous work and large fluctuations due to micro-EHL are also presented. Validation of the multiscale method with a deterministic topography is provided demonstrating good accuracy and efficiency.Keywords: EHL; micro-EHL; Surface Topography; Metamodelling. INTRODUCTIONThe Elastohydrodynamic Lubrication (EHL) of line contacts generates high pressures which result in the bounding surfaces being separated by a thin lubricant film [1]. Surface topography can be of a similar scale to the film thickness and therefore has an effect on the performance of the tribological system [2]. For example Etsion et al. [3] showed that surface features can reduce the contacting friction of an EHL contact and Greenwood and Johnson [4] demonstrated that transverse waviness caused ripples in EHL pressure distributions. Reconciling the disparity in scales between surface topography and the contact region is a challenging computational problem for which many authors have sought solutions. Waviness in EHL has been modelled for example by Hooke [5] and Venner and Lubrecht [6] who investigated the amplitude reduction effect, but no such general method for describing the influence of surface topography in EHL as yet exists. The level of discretisation necessary to successfully solve fully deterministic problems, where both the contact region and surface topography are modelled simultaneously, has led to the development of homogenisation based models [7]. In such models information pertaining to the EHL of a topographical feature is characterised over a range of variables and subsequently coupled into a model for the EHL of the contact region. Periodicity in the lubricant flow and topographical features ensure that homogenisation of the solutions obtained at the smaller scale produces data which represents the behaviour of the larger scale [8,9]. Solutions to the EHL problem which are deterministic by nature also remain the subject of a significant amount of recent research [10][11][12][13][14][15][16][17].Patir and Cheng [18] first developed a two-scale model to include the effects of surface topography in hydrodynamic lubrication known as the flow factors method. In this approach the terms of the Reynolds equation, which describes the lubricant flow in the contact under smooth surface assumptions [19], were multiplied by flow factors which include the homogenised effects of surface topography. Sahlin, et al. [2...

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An adaptive finite element procedure for fully-coupled point contact elastohydrodynamic lubrication problems

Cited by 14 publications

References 41 publications

Effect of Oil Temperature on Load Capacity and Friction Power Loss in Point Contact Elasto-hydrodynamic Lubrication

Effect of Oil Temperature on Load Capacity and Friction Power Loss in Point Contact Elasto-hydrodynamic Lubrication

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

Heterogeneous Multiscale Methods for modelling surface topography in Elastohydrodynamic Lubrication line contacts

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