The lubrication of lightly loaded cylinders in combined rolling, sliding and normal motion with couple stress fluid

Bujurke, N. M.; Naduvinamani, N. B.

doi:10.1016/0020-7403(90)90001-y

Cited by 32 publications

(19 citation statements)

References 14 publications

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“…The results are obtained for eccentricity ratio e ranging from 0.1 to 0.9, length to diameter ratio k of 1.0 and couple stress parameter L of 0.0, 0.2 and 0.4 [21][22][23][24][25][26][27][28][29][30], (L = 0.0 is the Newtonian lubricant case). The results are determined for magnetic coefficient c = 0.0 (non-magnetic lubricant case) and c = 0.1 (magnetic lubricant case) [17,34].…”

Section: Resultsmentioning

confidence: 99%

“…It was found that the larger the chain length of the lubricant or additive molecule, the greater the effects of couple stresses. Bujurke and Naduvinamani [26] investigated the lubrication of lightly loaded cylinders in combined rolling, sliding, and normal motion with a couplestress fluid as lubricant under cavitation boundary conditions. It was found that the load capacity and the frictional drag increased as the squeeze velocity increased.…”

Section: Introductionmentioning

confidence: 99%

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Static Performance of Finite Hydrodynamic Journal Bearings Lubricated by Magnetic Fluids with Couple Stresses

Nada

Osman

2007

Tribol Lett

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Based upon the Stokes micro-continuum theory, the problem of lubrication of finite hydrodynamic journal bearing lubricated by magnetic fluids with couple stresses is investigated. By taking into account the couple stresses due to the microstructure additives and the magnetic effects due to the magnetization of the magnetic fluid, modified Reynolds equation is obtained. The effects of couple stresses are studied by defining the couple stress parameter L that can be considered as a measure of the chain length of the additive molecule. The magnetic effects of the magnetic fluid are investigated by the magnetic coefficient c. Using the finite-difference technique and for different values of couple stress parameter and magnetic coefficient, the Reynolds equation is solved, and pressure distributions are obtained. The bearing static characteristics namely load carrying capacity, attitude angle, friction coefficient, and side leakage flow are determined. The results indicate that the influence of couple stresses and magnetic effects on the bearing characteristics are significantly apparent. It is concluded that fluids with couple stresses are better than Newtonian fluids. The improvement of the bearing characteristics is enhanced if the magnetic effects are present.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Static Performance of Finite Hydrodynamic Journal Bearings Lubricated by Magnetic Fluids with Couple Stresses

Nada

Osman

2007

Tribol Lett

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“…Bujurke and Naduvinamani [19] have included the effect of surface roughness on the squeeze film lubrication between anisotropic porous rectangular plates and predicted the sensitivity of the maximum load to the roughness parameter. Many investigators used this theory to analyze the lubrication characteristics of various bearing systems such as slider bearings [20,21], journal bearings, and squeeze film bearings [22,23]. Since the effect of couple stresses is significant and the roughness cannot be avoided, it is worth to investigate the combined effects of these on the bearing performance.…”

Section: Introductionmentioning

confidence: 99%

Effect of Surface Roughness and Couple Stresses on Squeeze Films between Curved Annular Plates

Basti

2013

ISRN Tribology

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The combined effects of couple stresses and surface roughness patterns on the squeeze film characteristics of curved annular plates are studied. The Stokes (1966) couple stress fluid model is included to account for the couple stresses arising due to the presence of microstructure additives in the lubricant. In the context of Christensen's (1969) stochastic theory for the lubrication of rough surfaces, two types of one-dimensional roughness patterns (circumferential and radial) are considered. The governing modified stochastic Reynolds type equations are derived for these roughness patterns. Expressions for the mean squeeze film characteristics are obtained. Numerical computations of the results show that the circumferential roughness pattern on the curved annular plate results in more pressure buildup whereas performance of the squeeze film suffers due to the radial roughness pattern for both concave and convex pads. Further the squeeze film time is longer (shorter) for the circumferential (radial) roughness patterns. Improved squeeze film characteristics are predicted for the couple stress lubricant.

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“…For couple stress fluids, there have been a number of studies carried out due to its widespread industrial and scientific applications, such as the work of Stokes [20], Ramanaiah [21], Sinha and Singh [22], Bujurke and Naduvinami [23], Gupta and Sharma [24], Mokhiamer et al [25], Li-Wang et al [26] and many others. Couple stress fluids are the fluids consisting of rigid, randomly oriented particles suspended in a viscous medium, such as blood fluids, lubricants containing small amount of high polymer additive, electro-rheological fluids and synthetic fluids.…”

Section: Introductionmentioning

confidence: 99%

“…Sinha and Singh [22] did a research on the effects of couple stresses on the lubrication of rolling contact bearings, and Bujurke and Naduvinamani [23] made an investigation on the lubrication of lightly loaded cylinders with combined rolling, sliding and normal motion with a couple stress fluid as lubricant. These studies were to investigate the effects of the couple stress on the lubrication and all found that using a couple-stress fluid as a lubricant leads to an increase in the load capacity and a reduction in the coefficient of friction compared with Newtonian lubricants.…”

Section: Introductionmentioning

confidence: 99%

Exact solutions for two dimensional flows of couple stress fluids

Islam

Zhou

2007

Z. angew. Math. Phys.

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Exact solutions are derived for the class of two dimensional couple stress flows. This class consists of flows for which the vorticity distribution is proportional to the stream function perturbed by a uniform stream. The solutions are obtained by applying the so-called inverse method which makes certain hypothesis a priori on the form of the velocity field and pressure without making any on the boundaries of the domain occupied by the fluid. Exact solutions are obtained for both steady and unsteady cases.

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The lubrication of lightly loaded cylinders in combined rolling, sliding and normal motion with couple stress fluid

Cited by 32 publications

References 14 publications

Static Performance of Finite Hydrodynamic Journal Bearings Lubricated by Magnetic Fluids with Couple Stresses

Static Performance of Finite Hydrodynamic Journal Bearings Lubricated by Magnetic Fluids with Couple Stresses

Effect of Surface Roughness and Couple Stresses on Squeeze Films between Curved Annular Plates

Exact solutions for two dimensional flows of couple stress fluids

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