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Physics of Fluids, 2022
For heavy-duty bearings with low-viscosity lubricant, asperities may contact near the minimum nominal film thickness, while turbulence may develop in the area with large film thickness. When bearings encounter transient impact or unsteady loads, the influence of turbulence and surface roughness is relatively complex.
Fangrui Lv +3 more
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For heavy-duty bearings with low-viscosity lubricant, asperities may contact near the minimum nominal film thickness, while turbulence may develop in the area with large film thickness. When bearings encounter transient impact or unsteady loads, the influence of turbulence and surface roughness is relatively complex.
Fangrui Lv +3 more
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Transient Lubricating Films With Inertia—Turbulent Flow
Journal of Tribology, 1984This paper presents some new equations for the treatment of turbulent lubricating films when the effects of inertia cannot be neglected. The eddy-viscosity concept is used to represent the turbulent stresses in terms of mean-velocity gradient. Transient and steady-state operation are both considered by means of a generalized stream-function-pressure ...
H. G. Elrod, I. Anwar, R. Colsher
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On Gas Lubrication in Turbulent Regime
Journal of Basic Engineering, 1964This paper analyzes first the transient conditions from laminar to turbulent regime for gas lubricated bearings. Then the pressure equation is deduced for self-acting gas-lubricated bearing by using Prandtl’s mixing length theory. A simple method for determining the pressure and the operating characteristics for bearings operating at high numbers H is ...
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Mixed-lubrication analysis of misaligned bearing considering turbulence
Tribology International, 2018Abstract Some bearings operate in mixed-lubrication regime due to the low rotational speed and the heavy load and misalign due to shaft's gravity. For large bearings, the maximum film thickness is much larger than minimum nominal film thickness and turbulence may locally develop. This paper proposes an approach to analyze misaligned mixed-lubrication
Fangrui Lv +3 more
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Physics of Fluids, 2022
This paper numerically investigates the effect of turbulence and journal misalignment on the lubrication characteristics of micro-grooved bearings with low-viscosity lubricant. The generalized average Reynolds equation satisfying the mass conservation cavitation algorithm is developed by integrating the average flow model proposed by Patir and Cheng ...
Peng Li +6 more
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This paper numerically investigates the effect of turbulence and journal misalignment on the lubrication characteristics of micro-grooved bearings with low-viscosity lubricant. The generalized average Reynolds equation satisfying the mass conservation cavitation algorithm is developed by integrating the average flow model proposed by Patir and Cheng ...
Peng Li +6 more
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An Expression of Reynolds Stresses in Turbulent Lubrication Theory
Journal of Tribology, 1992This paper proposes an alternative model of Reynolds stresses for turbulent lubrication theory. The approach relies on Prandtl’s mixing length theory which is based on a modified Van Driest mixing formula [1]. However, unlike the previous theories [2, 3] the proposed equation is capable of accounting for the effect of shear stress gradient on the ...
A. K. Tieu, P. B. Kosasih
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The homogenization method of roughness analysis in turbulent lubrication
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2013The 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.
Mustapha Lahmar +2 more
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On the Determination of Friction Forces in Turbulent Lubrication
A S L E Transactions, 1965The mixing length theory, used previously for the determination of the velocity profiles and pressure distributions in turbulent films is now employed in order to determine the friction stresses To, Th on the two lubricated surfaces and their dependence on the Reynolds number and on the pressure distribution. Thus, it results that the curves τo(Bxτ and
V. N. Constantinescu, S. Galetuse
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Three-dimensional laminar and turbulent lubrication in journal bearings
Wear, 1990Abstract The three-dimensional motion in the lubricant layer of a journal bearing, operating from laminar to turbulent flow conditions, is analysed theoretically. The velocity and pressure fields are calculated from the governing differential equations using an iterative numerical method.
K. Venkateswarlu +3 more
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A Transition-Turbulent Lubrication Theory Using Mixing Length Concept
Journal of Tribology, 1993This paper applies the recently introduced Reynolds stress expression (Tieu and Kosasih, 1992) in the transition-turbulent lubrication analysis. The Reynolds stress is modeled using the mixing length expression which is able to account for the effect of local shear stress gradient, and it can be extended to apply in the transition regime.
P. B. Kosasih, A. K. Tieu
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