Non-Newtonian Effects of Multigrade Oils on Journal Bearing Performance

Gecim, B.

doi:10.1080/10402009008981968

Cited by 50 publications

(21 citation statements)

References 10 publications

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“…The Rabinowicz non-Newtonian fluid model was applied. However, there are different models describing the non-Newtonian behaviour of lubricant, for example, the power-law fluid model to account for non-Newtonian fluid behaviour 28,29) or the approach that involves solving two-dimensional momentum equations and a constitutive equation modelling non-Newtonian fluid behaviour based on the cross-film integrals of viscosity 30,31) . Most of these models involve solving PDEs and they will be applied in the future work, after a 2D unified approach is developed.…”

Section: Discussionmentioning

confidence: 99%

A Unified Computational Approach to the Optimization of Surface Textures:One Dimensional Hydrodynamic Bearings

2010

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In tribological applications, surface textures are used to increase load capacity and reduce friction losses in hydrodynamic lubricated contacts. However, there is no systematic, efficient and general approach allowing for the optimization of surface texture shapes to give an optimal performance. The work conducted is, in most cases, by "trial and error", i.e. changes are introduced and their effects studied. This is time consuming and inefficient. In this paper, a unified computational approach to the optimization of texture shapes in bearings is proposed. The approach aims at finding the optimal texture shape that supports the maximum load and/or minimizes friction losses in one dimensional hydrodynamic bearings. The texture shape optimization problem is transformed into a nonlinearly constrained mathematical programming problem with general constraints that can be solved using optimal control software. Load-carrying capacity or friction force of a bearing becomes an objective functional that is maximized or minimized, subject to: (i) any Reynolds equations given by first order ordinary differential equations, (ii) pressure boundary conditions and (iii) functions/parameters that define the surface texture shape. This newly developed approach is demonstrated on examples of parallel textured hydrodynamic bearings. The effects of non-Newtonian fluids, cavitation and viscosity varying with temperature are considered.

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Section: Discussionmentioning

confidence: 99%

A Unified Computational Approach to the Optimization of Surface Textures:One Dimensional Hydrodynamic Bearings

2010

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“…In 1971, Wada and Hayashi [24] clarified the non-Newtonian characteristics of oil. In 1990, Gecim [25] used the power-law model to study the non-Newtonian effects of two oils under different temperature by the experimental. Therefore, this paper adopt power-law model [26] to simulate the pressure ripple changes of the non-Newtonian fluid in trapped volume of gear pumps.…”

Section: Calculation Methodsmentioning

confidence: 99%

Pressure ripple of gear pumps affected by air content on trapped volume

Hao¹,

Zhou²,

Liu³

et al. 2016

J. vibroeng.

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A general assumption about fluid power systems is that the pressure ripple of trapped volume is a primary source for fluid-borne noise. Whereas the high frequency vibration characteristics generated by pressure fluctuations of trapped volume are different under different air content in the oil. This paper presents the non-Newtonian fluid models to describe the oil flow condition in external gear pumps. In this analysis, pressure ripple due to compressibility of fluid is considered, and the effect of pressure ripple in the trapped volume of external gear pumps has been investigated by comparing with 8 % air content and 10 % air content in the oil. It was found that the amplitude of pressure fluctuation would drop about 2.5 MPa with the increase 2 % of the air content under the same conditions of load and speed. The whole work was performed on the computational fluid dynamics (CFD) environment, an efficient tool for the simulation of dynamic engineering systems, and more particularly of fluid power.

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“…Одной из основных задач при анализе подшипников скольжения с коническими поверхностями, является задача гидродинамического поведения смазочного слоя в коническом зазоре. Актуальность данной проблемы связана с решением технических задач по использованию подобного рода подшипников в качестве опорных устройств в гидравлических турбинах, машинах и аппаратах, где наряду с качествами, присущими цилиндрическим подшипникам должны проявляться качества опорного устройства [1][2][3][4][5][6][7]. Достоинствами конических подшипников являются их малые габариты, по сравнению с цилиндрическими, и надежность в эксплуатации.…”

Section: Introductionunclassified

Peculiarities of physical modeling of hydrodynamics of flow in conical slide bearings

Разави¹,

Koval²

2018

Mechanics and Advanced Technologies

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Исследование гидродинамики потока в конических подшипниках трения является в настоящее время одной из актуальных задач в машиностроении, так как подобного рода подшипники используются в качестве опорных устройств и получили широкое распространение в целом ряде механических и гидравлических систем, в частности, в турбинах, системах гидропривода и в автомобильной промышленности. Особенностью подобного рода подшипников является то, что они имеют более сложную, по сравнению с цилиндрическими, конструкцию и недостаточно полно изучена гидродинамика потока внутри этих устройств. К сожалению, теоретические исследования подобных задач в настоящее время не является полным и результаты таких исследований не всегда совпадают с экспериментальными данными. Учитывая это, возникает необходимость в проведении экспериментальных исследований с целью получения зависимостей момента трения в коническом подшипнике скольжения и величин на него влияющих, например, толщиной смазывающего слоя, реологических характеристик смазки и кривизны поверхности. Данная работа посвящена физическому моделированию конических подшипников трения с учетом реологических свойств смазочных материалов, то есть рассматриваются проблемы связанные с определением момента трения в коническом зазоре с учетом реологических особенностей смазки.

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Non-Newtonian Effects of Multigrade Oils on Journal Bearing Performance

Cited by 50 publications

References 10 publications

A Unified Computational Approach to the Optimization of Surface Textures:One Dimensional Hydrodynamic Bearings

A Unified Computational Approach to the Optimization of Surface Textures:One Dimensional Hydrodynamic Bearings

Pressure ripple of gear pumps affected by air content on trapped volume

Peculiarities of physical modeling of hydrodynamics of flow in conical slide bearings

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