Pressure and Shear Flow in a Rough Hydrodynamic Bearing, Flow Factor Calculation

1997 ◽  
Vol 119 (3) ◽  
pp. 549-555 ◽  
Author(s):  
L. Lunde ◽  
K. To̸nder
Keyword(s):  
Finite Element Method ◽  
Surface Roughness ◽  
Finite Element ◽  
Shear Flow ◽  
Reynolds Equation ◽  
Flow Model ◽  
The Finite Element Method ◽  
Average Flow ◽  
Hydrodynamic Bearing ◽  
Average Flow Model

The lubrication of isotropic rough surfaces has been studied numerically, and the flow factors given in the so-called Average Flow Model have been calculated. Both pressure flow and shear flow are considered. The flow factors are calculated from a small hearing part, and it is shown that the flow in the interior of this subarea is nearly unaffected by the bearing part’s boundary conditions. The surface roughness is generated numerically, and the Reynolds equation is solved by the finite element method. The method used for calculating the flow factors can be used for different roughness patterns.

A mass-conservative average flow model based on finite element method for complex textured surfaces

2013 ◽  
Vol 56 (10) ◽  
pp. 1909-1919 ◽  
Author(s):  
Yi Xie ◽  
YongJian Li ◽  
ShuangFu Suo ◽  
XiangFeng Liu ◽  
JingHao Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Flow Model ◽  
Textured Surfaces ◽  
Average Flow ◽  
Model Based ◽  
Average Flow Model ◽  
Element Method

scholarly journals Surface Roughness Effects in Hydrodynamic Lubrication: The Flow Factor Method

1983 ◽  
Vol 105 (3) ◽  
pp. 458-463 ◽  
Author(s):  
J. H. Tripp
Keyword(s):  
Surface Roughness ◽  
Reynolds Equation ◽  
Flow Model ◽  
Hydrodynamic Lubrication ◽  
Perturbation Expansion ◽  
Ensemble Averaging ◽  
Roughness Effects ◽  
Average Flow ◽  
Point Correlation ◽  
Average Flow Model

The average flow model of Patir and Cheng [1, 2] for obtaining an average Reynolds equation in the presence of two dimensional surface roughness is extended and generalized. Expectation values of the flow factors appearing in the formalism are calculated by means of a perturbation expansion of the pressure in a nominal parallel film. Terms in the series are evaluated using the unperturbed Green function, which permits ensemble averaging to be performed directly on the solution. Calculations are carried to second order, which involves only two point correlation functions of the two rough surfaces. Perturbation results agree well with results of the earlier numerical simulation until surface contact becomes important when both approaches are inadequate. The theory displays the dependence of the flow factors on the roughness parameters in simple closed form, leading to improved understanding of the average flow method.

An Evaluation of the Average Flow Model [1] for Surface Roughness Effects in Lubrication

1980 ◽  
Vol 102 (3) ◽  
pp. 360-366 ◽  
Author(s):  
J. L. Teale ◽  
A. O. Lebeck
Keyword(s):  
Surface Roughness ◽  
Flow Model ◽  
Two Dimensional ◽  
Roughness Effects ◽  
Important Conclusion ◽  
Average Flow ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Average Flow Model

The average flow model presented by Patir and Cheng [1] is evaluated. First, it is shown that the choice of grid used in the average flow model influences the results. The results presented are different from those given by Patir and Cheng. Second, it is shown that the introduction of two-dimensional flow greatly reduces the effect of roughness on flow. Results based on one-dimensional flow cannot be relied upon for two-dimensional problems. Finally, some average flow factors are given for truncated rough surfaces. These can be applied to partially worn surfaces. The most important conclusion reached is that an even closer examination of the average flow concept is needed before the results can be applied with confidence to lubrication problems.

Effect of fluid forcing on vestibular hair bundles

2005 ◽  
Vol 15 (5-6) ◽  
pp. 263-278
Author(s):  
J.-H. Nam ◽  
J.R. Cotton ◽  
J.W. Grant
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shear Flow ◽  
Viscous Fluid ◽  
Hair Bundle ◽  
Structural Components ◽  
The Finite Element Method ◽  
Fluid Drag ◽  
Tip Link ◽  
Single Force

A dynamic 3-D hair bundle model including inertia and viscous fluid drag effects based on the finite element method is presented. Six structural components are used to construct the hair bundle – kinocilium, stereocilia, upper lateral links, shaft links, tip links, and kinocilial links. Fluid drag is distributed on the surface of cilia columns. Bundle mechanics are analyzed under two distinct loading conditions: (1) drag caused by the shear flow of the surrounding endolymph fluid (fluid-forced), (2) a single force applied to the tip of the kinocilium (point-forced). A striolar and a medial extrastriolar vestibular hair cell from the utricle of a turtle are simulated. The striolar cell bundle shows a clear difference in tip link tension profile between fluid-forced and point-forced cases. When the striolar cell is fluid forced, it shows more evenly distributed tip link tensions and is far more sensitive, responding like an on/off switch. The extrastriolar cell does not show noticeable differences between the forcing types. For both forcing conditions, the extrastriolar cell responds serially – the nearest tip links to the kinocilium get tensed first, then the tension propagates to the farther tip links.

scholarly journals The use of the finite-element method for the simulation of ground water flow

1988 ◽  
Vol 7 (4) ◽  
pp. 174-183
Author(s):  
G. J. Van Tonder ◽  
J. F. Botha
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ground Water ◽  
Water Flow ◽  
Flow Model ◽  
The Finite Element Method ◽  
Ground Water Flow ◽  
Available Information ◽  
Good Flow ◽  
Element Method

The present investigation is mostly concerned with the contribution that the finite-element method can make towards the simulation of ground water flow. After a brief introduction to the finite element method, it is applied to the Grootfontein dolomitic aquifer near Mafikeng/Mmabatho. This aquifer yields water for irrigation purposes as well as water for the township. By utilizing the available information a good flow model was constructed for this aquifer. The model is considered calibrated and verificated.

Numerical Calculation and Analysis of Water-Lubricated Stern Bearing Considering Elastic Hydrodynamic

2014 ◽  
Vol 1061-1062 ◽  
pp. 653-657
Author(s):  
Gang Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Calculation ◽  
Film Thickness ◽  
Reynolds Equation ◽  
Hydrodynamic Lubrication ◽  
Water Film ◽  
Polymer Materials ◽  
The Finite Element Method ◽  
Metal Materials

The deformation of marine water-lubricated stern bearing which the lining materials are polymer materials is much bigger than the bearing built with metal materials. So, in order to improve the calculate accuracy of elastic hydrodynamic, it is necessary to consider the deformation of the lining. Both pressure and thickness distributions of water film which contrasts with the hydrodynamic lubrication are presented by the Reynolds equation, and combining with the elastic deformation of the stern bearing solved by using the finite element method theory. The result shows that the stern bearing water film pressure of elastic hydrodynamic lubrication is lower than that of hydrodynamic lubrication, while the water film thickness is larger.

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