Roughness Effects in Porous Circular Squeeze-Plates With Arbitrary Wall Thickness

1983 ◽  
Vol 105 (1) ◽  
pp. 90-95 ◽  
Author(s):  
J. Prakash ◽  
K. Tiwari
Keyword(s):  
Wall Thickness ◽  
Hydrodynamic Lubrication ◽  
Stochastic Theory ◽  
Squeeze Film ◽  
Approximate Analysis ◽  
Tabular Form ◽  
Circular Plates ◽  
Roughness Effects ◽  
Influencing Parameters ◽  
Effect Of Surface

The stochastic theory of hydrodynamic lubrication of rough surfaces is used to study the effect of surface roughness on the response of a squeeze film between two circular plates when one plate has a porous facing. An exact solution is given for the film pressure and pressure in the bearing matrix, valid for arbitrary wall thickness. The results are presented in tabular form and a comparison is made with an earlier approximate analysis to determine the range of influencing parameters for which the approximate solution is acceptable.

An Analysis of the Squeeze Film Between Rough Porous Rectangular Plates With Arbitrary Porous Wall Thickness

1984 ◽  
Vol 106 (2) ◽  
pp. 218-222 ◽  
Author(s):  
J. Prakash ◽  
K. Tiwari
Keyword(s):  
Wall Thickness ◽  
Hydrodynamic Lubrication ◽  
Stochastic Theory ◽  
Porous Wall ◽  
Squeeze Film ◽  
Rectangular Plates ◽  
Approximate Analysis ◽  
Bearing Material ◽  
Porous Walls ◽  
Influencing Parameters

The Christensen’s stochastic theory of hydrodynamic lubrication of rough surfaces is used to study the effects of surface roughness on the response of the squeeze film between rectangular plates when one plate has a porous facing. An exact solution, valid for arbitrary wall thickness, is obtained for the film pressure and pressure in the bearing material. A comparison is made with an earlier approximate analysis, applicable to thin porous walls to determine the range of influencing parameters for which the approximate solution is acceptable.

Lubrication of a Porous Bearing With Surface Corrugations

1982 ◽  
Vol 104 (1) ◽  
pp. 127-134 ◽  
Author(s):  
J. Prakash ◽  
K. Tiwari
Keyword(s):  
Surface Roughness ◽  
Hydrodynamic Lubrication ◽  
Rough Surfaces ◽  
Stochastic Theory ◽  
Circular Plates ◽  
Operating Characteristics ◽  
Roughness Effects ◽  
Porous Bearing

The paper considers the surface roughness effects in hydrodynamic porous bearings. On the basis of stochastic theory of hydrodynamic lubrication of rough surfaces developed by Christensen, different forms of Reynolds type equations, as applicable to a general porous bearings are derived for various types of surface roughness pattern. To illustrate the functional effects of surface roughness on the operating characteristics of a porous bearing, the case of nonrotating circular plates in normal approach is analyzed. It is shown that surface roughness may considerably influence the operating characteristics of porous bearings. The direction of the influence, however, depends upon the type of roughness assumed.

Surface Roughness Effects in Infinitely Long Porous Journal Bearings

1999 ◽  
Vol 121 (1) ◽  
pp. 139-147 ◽  
Author(s):  
K. Gururajan ◽  
J. Prakash
Keyword(s):  
Surface Roughness ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Rough Surfaces ◽  
Stochastic Theory ◽  
Journal Bearings ◽  
Roughness Effects ◽  
Effect Of Surface

Christensen’s stochastic theory of hydrodynamic lubrication of rough surfaces is used to study the effect of surface roughness in an infinitely long porous journal bearing operating under steady conditions. It is shown that the surface roughness considerably influences the bearing performance; the direction of the influence depends on the roughness type.

scholarly journals Effect of Surface Roughness on the Squeeze Film Characteristics of Circular Plates in the Presence of Conducting Couplestress Fluid and Transverse Magnetic Field

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Syeda Tasneem Fathima ◽  
N. B. Naduvinamani ◽  
J. Santhosh Kumar ◽  
B. N. Hanumagowda
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Transverse Magnetic ◽  
Squeeze Film ◽  
Circular Plates ◽  
Roughness Effects ◽  
Modified Equations ◽  
Load Carrying ◽  
Film Characteristics ◽  
Effect Of Surface

The combined effect of surface roughness and magnetic field on the performance characteristic of the circular plates lubricated with conducting couplestress fluid (CCSF) has been studied. On the basis of the Christensen Stochastic model, the generalized stochastic Reynold’s equation is derived. Modified equations for the nondimensional pressure, load load-carrying capacity, and squeeze film time are derived. The results are presented both numerically and graphically and compared with conducting smooth surface case. It is observed that the surface roughness effects are more pronounced for couplestresses as compared to nonconducting Newtonian fluid (NCNF) in the presence of magnetic field.

scholarly journals EFFECT OF SURFACE ROUGHNESS ON CHARACTERISTICS OF MAGNETIC FLUID BASED SQUEEZE FILM BETWEEN POROUS CIRCULAR PLATES

2020 ◽  
Vol 14 (1) ◽  
pp. 90-98
Author(s):  
P. L. Thakkar ◽  
H. C. Patel
Keyword(s):  
Surface Roughness ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Type Equation ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Circular Plates ◽  
Load Carrying ◽  
Better Than ◽  
Effect Of Surface

The effect of surface roughness on characteristics of magnetic fluid based squeeze film between porous circular plates is hypothetically analysed. The pressure distribution is obtained by solving concern Reynolds type equation with suitable boundary conditions and the result is utilized to obtain load carrying capacity. It is concluded that the load carrying capacity increases with increasing magnetization, while load carrying capacity decreases due to the standard deviation. It is observed that the negatively skewed roughness and negative mean increase the load carrying capacity. It is also observed that the magnetic fluid lubricant improves the performance of a bearing system, thereby, suggesting that the performance of the bearing with magnetic fluid lubricant is better than the conventional lubricant.

A Theory of Cavitation in an Oscillatory Oil Squeeze Film

2005 ◽  
Author(s):  
D. C. Sun ◽  
Zhiming Zhang ◽  
Wen Wang ◽  
Meili Sun ◽  
Xiaoyang Chen
Keyword(s):  
Subsequent Development ◽  
Mass Conservation ◽  
Air Entrainment ◽  
Squeeze Film ◽  
Circular Plates ◽  
Cavitation Phenomenon ◽  
Cavitation Region ◽  
Underlying Mechanisms ◽  
Oil Films ◽  
Effect Of Surface

The cavitation of oil films in bearings subjected to dynamic loads is not well understood. In order to compute reliably the performance of dynamically loaded bearings, it is important to know the underlying mechanisms of the cavitation phenomenon and be able to predict its occurrence and subsequent development. From previous studies (Sun and Brewe, 1992; Sun, Brewe and Abel, 1993) the following features of cavitation in submerged bearings (i.e. with no air entrainment) are known: (1) Cavitation is confined to one region, which contains residual oil filaments of the fractured film. (2) The pressure in the cavitation region is the vapor pressure of oil. (3) Tensile stress is present in the oil film outside the cavitation region. (4) The occurrence of cavitation requires not only a low pressure level but also some other condition. In this paper a new cavitation model is proposed, that incorporates the above features, considers the effect of surface tension, and preserves mass conservation in the cavitation region. The model is applied to an oscillatory oil squeeze film bounded between two parallel circular plates, a problem that has been extensively studied in the past (Hayes and Feiten, 1964; Rodrigues, 1970; Parkins and May-Miller, 1984; Boedo and Booker, 1995; Optasanu and Bonneau, 2000). New results derived from the model are presented and compared with those of previous studies.

The Hydrodynamic Lubrication of Rough Bearing Surfaces of Finite Width

1971 ◽  
Vol 93 (3) ◽  
pp. 324-329 ◽  
Author(s):  
H. Christensen ◽  
K. Tonder
Keyword(s):  
Surface Roughness ◽  
Theoretical Analysis ◽  
Hydrodynamic Lubrication ◽  
Stochastic Theory ◽  
Finite Width ◽  
Operational Factors ◽  
Effect Of Surface

The paper describes a theoretical analysis of the effects of surface roughness in a finite width bearing. The analysis is based upon a stochastic theory of hydrodynamic lubrication developed previously. It is shown how the effect of surface roughness on the bearing characteristics is closely tied up with features of nominal geometry as well as with operational factors.

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

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Dhanapal P. Basti
Keyword(s):  
Surface Roughness ◽  
Couple Stress ◽  
Fluid Model ◽  
Stochastic Theory ◽  
Squeeze Film ◽  
Couple Stresses ◽  
Annular Plates ◽  
The Mean ◽  
Film Characteristics ◽  
Effect Of Surface

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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