Surface roughness effects in lubrication

proceedings of the 4th Leeds-Lyon Symposium on Tribology, held in the Laboratoire de mécanique des contacts, Institut national des sciences appliquées de Lyon, France, September, 1977 by Leeds-Lyon Symposium on Tribology (4th 1977 Lyon, France)

Publisher: Mechanical Engineering Publications for the Institute of Tribology, Leeds University and the Institut national des sciences appliquées de Lyon in London

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Cover of: Surface roughness effects in lubrication | Leeds-Lyon Symposium on Tribology (4th 1977 Lyon, France)
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Edition Notes

Includes bibliographical references and index.

Statementedited by D. Dowson ... [et al.].
ContributionsDowson, D., University of Leeds. Institute of Tribology., Institut national des sciences appliquées de Lyon.
LC ClassificationsTJ1075.A2 L43 1977
The Physical Object
Paginationix, 352 p. :
Number of Pages352
ID Numbers
Open LibraryOL4489451M
ISBN 100852984103
LC Control Number79318989

  The global and local effects of roughness, the effects of sliding and the transition to dry contact will be included. Finally, examples of industrial applications will be presented where roughness plays a major role in function; at the end, new challenges in the modelling of surface roughness effects in elastohydrodynamic lubrication will be Cited by: Effects of electrodouble layer (EDL) and surface roughness on lubrication theory W.-L. Li* Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Chien Kung Road, Kaohsiung , Taiwan Received 27 February ; accepted 18 July In the present work, surface roughness measurements were made using stylus and optical profilometry on coated stainless steel coupons. For the tribological evaluations coated disks are rubbed against superalloy pins in a pin-on-disk tribometer. Materials PS is a plasma sprayed, composite, solid lubricant coating that employs a nickel-molybdenum-File Size: 8MB. On the effects of surface roughness in lubrication. to a certain problem may be regarded as an averaging technique as well as it provides information about the induced effects of local surface roughness. Homogenization inflicts no restrictions on the surface roughness representation other than the representative part of the chosen surface Cited by: 8.

THE EFFECT OF SURFACE ROUGHNESS ON THE PERFORMANCE OF FINISHE. S PART 1. ROUGHNESS CHARACTERIZATION AND STAIN PERFORMANCE KLAUS RICHTER WILLIAM C. FEIST MARK T. KNAEBE ABSTRACT In this study, the relationship between the morphological structure of the outside wood layer expressed as surface roughness, and the . This work presents a meta-analysis that compares the suitability of various parameters used to characterize wettability in tribological systems. It also examines the relationship between wettability and the friction factor for multiple lubricant-surface pairings. The characterization of wetting behavior was similar when using the contact angle between a lubricant and surface Cited by: 2. Even though the assumption of a single asperity is highly ideal, this study sheds some light on the effect of surface roughness on elastohydrodynamic lubrication. The results show that the film pressure tends to increase more than the steady state pressure, and in particular, the increase in pressure reaches a maximum as the asperity approaches Author: National Aeronautics and Space Administration NASA. A numerical solution for line contact elastohydrodynamic lubrication (EHL) occurring on the rough surface of heterogeneous materials with a group of particles is presented in this study. The film thickness disturbance caused by particles and roughness is considered into the solution system, and the film pressure between the contact gap generated by the particles and the surface roughness .

  The purpose of this paper is to discuss the combined effects of the deterministic surface roughness and porous structure on the lubrication property of the multi-layer bearing.,Digital filtering technique and Kozeny-Carman equation are used to simulate the random Gauss surface and the internal pore structure of the porous bearing, by: 8. main objective is to determine the effect of lubrication conditions on the surface roughness. T wo types of insert had been used in this research, which is different in geometry selection is radius m m and m m. Three other parameters were also considered in this study; feed rate, depth of cut and cutting speed. The three dimensional surface roughness parameters consider the surface as a two dimensional plane (x,y) with the third dimension (z) being height. The three dimensional surface roughness parameters were decided upon in due to the rise of the 3D surface . A simplified mathematical model has been developed for understanding the combined effects of surface roughness and couple stresses on the squeeze film behavior of poroelastic bearings in general and that of hip joints in particular. The cartilage is modeled as biphasic poroelastic matrix and synovial fluid is modeled as couple stress fluid. The modified form of averaged Reynolds Cited by: 1.

Surface roughness effects in lubrication by Leeds-Lyon Symposium on Tribology (4th 1977 Lyon, France) Download PDF EPUB FB2

Surface Roughness Effects in Hydrodynamic and Mixed Lubrication on *FREE* shipping on qualifying offers. Surface Roughness Effects in Hydrodynamic and Mixed LubricationManufacturer: NYAmerican Society of Mechanical Engineers.

Abstract. The following deals with effects of surface roughness in hydrodynamic lubrication. Although most of the effects described apply Surface roughness effects in lubrication book several types of tribological devices, the discussion is essentially related to bearings.

The main reason Surface roughness effects in lubrication book this is simply the suitability of bearings for illustration by: 2. The effect of roughness of surfaces of a slider bearing on the load-carrying capacity and friction force, is studied.

The distinction is made between waviness and roughness, the latter being treated as a random quantity which may be characterized by a probability density function, determined by: RANDOM SURFACE ROUGHNESS EFFECTS IN MICROASPERITY LUBRICATION Prerit Vyas Research Assistant [email protected] Lyndon.

Stephens Associate Professor [email protected] University of Kentucky, Department of Mechanical Engineering RGAN Building, Lexington, KY, USA Phone: () ext Fax:. Zhu presented a numerical solution of the effects of the surface roughness on the pressure spike and the film constriction.

e surface roughness could not only affect the distribution of film. Surface roughness effects are modelled on the local cell level, while the actual lubrication problem is solved on the global level. Surface roughness influences contact mechanics, when surfaces are boundary lubricated, as well as hydrodynamic film formation.

The all-regimes lubrication model is applied to thrust bearings and wet by: The effects of surface roughness on hydrodynamic lubrication problems were usually studied by creating a model with a general roughness pattern, and most roughness models were included in the film thickness equation (Ai and Cheng, ).File Size: KB.

The results of this study suggest that under the fully starved condition, a lubrication film with high limiting shear stress was formed on the contact surfaces. This film inhibited wear in the rubbing process. Furthermore, the duration over which the film prevented wear decreased with increasing surface : Takefumi Otsu, Kyoichi Komatsu, Shinji Hashimura.

Results show that the roughness amplitude imposes a strong influence on the magnificence of friction and the route of lubrication transition. It is also observed that transverse roughness would give rise to a smaller friction coefficient than the longitudinal one under the same operating by: Surface roughness, particle denting and contamination marks found on bearing raceways can induce stress concentrations and facilitate surface-initiated fatigue.

The lubricant film developed at the dent and related local surface stresses are also signifi- cant to the crack initiation mechanisms. Elastohydrodynamic lubrication (EHL) is a mode of lubrication of many mechanical components.

Because roughness of engineering surfaces is usually of the same order of magnitude as, or greater than, the average EHL film thickness, its influence ought to be taken into account when investigating EHL characteristics. running period and subsequently have no effect.

The effect of greasy or soapy film, if present, is more marked; it reduces the severity of surface interaction often by one or more orders of magnitude. This chapter covers the details on the analysis and measurement of surface roughness. Analysis of Surface Roughness. [Show full abstract] surface roughness can be reduced to certain extent by the positive effect of Shliomis model based ferrofluid lubrication.

Further, for this type of. In order to study the effect of surface roughness on the Elastohydrodynamic Lubrication (EHL) performance of cylindrical roller bearing, an EHL model of cylindrical roller bearing with three dimensional surface cosine roughness based on finite length line contact theory is established.

Surface roughness effects in lubrication. London: Mechanical Engineering Publications for the Institute of Tribology, Leeds University and the Institut national des sciences appliquées de Lyon, (OCoLC) Material Type: Conference publication: Document Type: Book: All Authors / Contributors: D Dowson; University of Leeds.

Institute of Tribology. The effect of surface roughness on EHL loads, speeds, and central film thicknesses is studied. The results indicate that for a constant central film thickness (1) increasing the surface roughness decreases the EHL load and (2) there is little variation in minimum film thickness as the surface roughness is by: The effect of surface roughness average of hypereutectic aluminum silicon alloys (with 16 wt% Si) on the friction and wear was investigated.

Various surface roughness average (Ra) of different degrees was verified as well as three different lo 20 and 30 N, speedsand rpm and relative humidity 77%. Different surface preparation techniques are resulted Cited by:   The effects of couple stress and surface roughness on the performances of a finite journal bearing are presented in detail.

Further, it is shown that lubricants with couple stress and surface roughness, not only increases the load capacity and decreases the friction coefficient, but also generates a lower bearing temperature : Vishwanath B.

Awati, Ashwini Kengangutti. The objective of the study is to investigate the combined effects of interaction of surface asperities and the non-Newtonian nature of lubricant on the HD performance of finite journal bearings bearings. The roughness takes the form of sinusoidal.

This paper describes measurements of the change in surface roughness of aluminiur~i strip due to cold rolling. Rolling is in the mixed lubrication regime, where there is both asperity contact and hydrodynamic action. The strip is in the as-received condition before rolling, with a continuous spectrum of roughness wave- lengths.

The Influence of Roughness on the Wear and Fric-tion Coefficient under dry and lubricated sliding Riyadh A. Al-Samarai1,Haftirman1,Khiarel Rafezi Ahmad2,Y. Al-Douri3 Abstract— The aim of the present research was to the effect of surface roughness of aluminum-silicon casting alloy on the friction and wear is Size: KB.

In addition, under very heavy loads, slow relative speed, insufficient surface area and scarcity of lubricant, the formation of thick film necessary for hydrodynamic lubrication becomes difficult and interacting surfaces contact each other at several locations and tribo–pairs operate in mixed lubrication.

This lubrication regime has been. DOI: / Corpus ID: oa. Effect of surface roughness on friction behaviour of steel under boundary lubrication @article{YamaguchiEffectOS, title={Effect of surface roughness on friction behaviour of steel under boundary lubrication}, author={Kazuma Yamaguchi and Chiaki Sasaki and Ryo Tsuboi and Mark Atherton and T.

Lubrication Regimes, with liquid present * - composite surface roughness = (r q1 2 + r q2 2)1/2 • In Liquid Lubrication, Regimes can be based on: Fluid Film Thickness • The Lambda Ratio is defined as the ratio of the fluid film thickness to the composite surface roughness* • λ > 3 → full film (thick film) lubrication, hydrodynamics.

The effect of surface roughness on the performance of hydrodynamic slider bearings is studied. A generalized form of surface roughness characterized by a stochastic random variable with non-zero mean, variance and skewness is assumed to define the bearing surface by: The main objective of this paper is to investigate the effect of surface roughness and lubricant viscosity on coefficient of friction in silicon nitride‐ steel rolling contact.

Two samples of silicon nitride with two different values of surface. Elastohydrodynamic lubrication (EHL) is a form of fluid film lubrication associated with nonconformal machine elements. The effects of surface kinematic conditions on EHL films are reviewed. Micro-EHL theory and the global effects of surface roughness are discussed.

The orientation and shape of surface irregularities such as transverse roughness and circular. The current research took into account the inferences of surface roughness and lubrication on scuffing for ADI.

The effect of various surface roughness values and two types of lubricants were evaluated based on the experimental data using ball-on-disc rig to better understand scuffing behavior affected by surface roughness and by: 1. of surface finishing and the deterministic surface roughness which is engineered to.

increase the lubrication characteristics of the hydro dynamically lubricated thrust ring. The effect of stochastic/random roughness can not be ignored when the roughness is of. the same amplitude as that of fluid film : Prerit Vyas. In this paper, the combined effect of surface roughness and bubbles content on the hydrodynamic performance of journal bearings is studied.

In the analysis, it is assumed that the bearing and shaft surfaces are covered with homogeneous isotropic roughness, the air bubbles are evenly distributed through the lubricant and the bubble size is very Cited by: 2.

The standard decoupled method with Newton-generalized minimum residual procedure performs poorly or may break down when used to solve certain elastohydrodynamic lubrication problems.

The authors Zargari et al., presented decoupled and coupled methods in which the limitations of the decoupled method for some set of physical parameters and slight variation in Author: Siddu C. Shiralashetti, Mounesha H. Kantli. The orientation of surface roughness pattern can improve the entraining velocity or in contrary make an obstacle against the fluid flow.

The first research on the effect of the surface roughness and the surface pattern on the lubrication problem was conducted by Patir. He introduced flow factors to study the surface roughness by: 1.Effects of Surface Roughness and Surface Force on the Thin Film Elastohydrodynamic Lubrication of Circular Contacts Li-Ming Chua, Jaw-Ren Linb, and Jiann-Lin Chena a Department of Mechanical and Automation Engineering, I-Shou University, Kaohsiung CityTaiwan, R.O.C.