On the Steady-State Performance of Isotropically Rough Porous Hydrodynamic Journal Bearings of Finite Width with Slip-Flow Effect

2005 ◽  
Vol 219 (11) ◽  
pp. 1249-1267 ◽  
Author(s):  
R Haque ◽  
S K Guha
Keyword(s):  
Steady State ◽  
Load Capacity ◽  
Practical Importance ◽  
Slip Flow ◽  
Type Equation ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Finite Width ◽  
Static Performance ◽  
Steady State Performance

The objective of the present article is to theoretically investigate the static performance characteristics of rough porous hydrodynamic journal bearings of finite width with the effect of slip flow at the porous-film interface on the basis of the Beavers-Joseph criterion. In the analysis, the roughness is uniformly distributed over the bearing surfaces, with no preferred position or direction in the surface. With the concept of a stochastic process for the isotropic roughness patterns, the steady-state performance characteristics in terms of load capacity, end flowrate, and frictional parameters are obtained at different parameters of practical importance by solving simultaneously the continuity equation of flow in the porous bush and the Reynolds-type equation using the finite difference techniques. According to the results obtained, this analysis reveals that the influence of roughness on the steady-state performance of the journal bearing is physically apparent and not negligible.

Effect of Slip Flow on the Steady-State Performance of Aerostatic Porous Journal Bearings

1984 ◽  
Vol 106 (1) ◽  
pp. 156-162 ◽  
Author(s):  
K. C. Singh ◽  
N. S. Rao ◽  
B. C. Majumdar
Keyword(s):  
Steady State ◽  
Slip Velocity ◽  
Load Capacity ◽  
Finite Thickness ◽  
Slip Flow ◽  
Velocity Slip ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Mass Rate ◽  
Steady State Performance

A theoretical solution is presented to predict the steady-state performance characteristics of aerostatic porous journal bearings of finite thickness considering three dimensional flow in the porous media. The analysis takes into account the velocity slip at the film bearing interface by using Beavers-Joseph criterion. Results are presented in dimensionless form for load capacity and mass rate of flow for different operating conditions and bearing dimensions. Solution is also obtained for modified slip velocity conditions and both the results are compared. It is observed that there is no agreement between two models except for few values of slip parameters. Hence, it is preferable to use the Beavers-Joseph model in order to account for all values of slip parameters. The effect of slip velocity on the static characteristics is discussed.

Static characteristics of hydrostatic doubled-layered porous journal bearings with slip flow including additives percolation into pores under coupled stress lubrication

2017 ◽  
Vol 232 (8) ◽  
pp. 927-939 ◽  
Author(s):  
Shitendu Some ◽  
Sisir K Guha
Keyword(s):  
Steady State ◽  
Reynolds Equation ◽  
Slip Flow ◽  
Journal Bearings ◽  
Static Characteristics ◽  
Governing Equations ◽  
Modified Reynolds Equation ◽  
Film Interface ◽  
Coupled Stress ◽  
Steady State Performance

A theoretical analysis of the steady-state characteristics of finite hydrostatic double-layered porous journal bearings dealing with the effects of slip flow at the fine porous layer–film interface and percolation of additives into pores under the coupled stress fluid lubrication is presented. Based on the Beavers–Joseph’s criterion for slip flow, the modified Reynolds equation applicable to finite porous journal bearings lubricated with coupled stress fluids have been derived. The governing equations for flow in the coarse and fine layers of porous medium incorporating the percolation of polar additives of lubricant and the modified Reynolds equation are solved simultaneously using finite difference method satisfying appropriate boundary conditions to obtain the steady-state performance characteristics for various parameter namely percolation factor, slip coefficient, bearing feeding parameter, coupled stress parameter, and eccentricity ratio. The results are exhibited in the form of graphs, which may be useful for design of such bearing.

Steady State Performance Characteristics of Single Pad Externally Adjustable Fluid Film Bearing in the Laminar and Turbulent Regimes

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
B. S. Shenoy ◽  
R. Pai
Keyword(s):  
Steady State ◽  
Performance Characteristics ◽  
Fluid Film ◽  
Radial Clearance ◽  
Wide Range ◽  
Tilting Pad ◽  
Load Carrying ◽  
Static Performance ◽  
Laminar And Turbulent Regimes ◽  
Steady State Performance

In an externally adjustable fluid film bearing, the hydrodynamic conditions can be changed as required in a controlled manner. The principal feature of the bearing is the facility to adjust its radial clearance and circumferential film thickness gradient. Unlike a tilting pad bearing, this bearing can have radial adjustments. The tilt adjustments are obtained by providing flexibility to the pad at one corner. This paper deals with the effect of turbulence on the steady state performance characteristics of a centrally loaded 120 deg single pad externally adjustable fluid film bearing. The bearing has an aspect ratio of 1 and operates over a wide range of eccentricity ratios with different radial and tilt adjustments. The Reynolds equation is solved numerically using the finite difference method. The linearized turbulence model of Ng and Pan (1965, “A Linearized Turbulent Lubrication Theory,” ASME J. Basic Eng., 87, pp. 675–688) as well as the simplified adiabatic model of Pinkus and Bupara (1979, “Adiabatic Solutions for Finite Journal Bearings,” ASME J. Lubr. Technol., 101, pp. 492–496) are incorporated in the solution scheme. The static performance characteristics calculated are presented in terms of load carrying capacity, attitude angle, friction variable, and Sommerfeld number. A comparative study with the combination of adjustments predicts that the static performance of the bearing is superior with negative radial and tilt adjustments.

A Generalized Solution on the Static Characteristics of Short Hydrodynamic Journal Bearings Using Harmonic Components

2016 ◽  
Author(s):  
Baisong Yang ◽  
Jiale Tian ◽  
Jian Zhou ◽  
Lie Yu
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Load Capacity ◽  
Harmonic Component ◽  
Generalized Solution ◽  
Journal Bearings ◽  
Hydrodynamic Bearing ◽  
Static Performance ◽  
Harmonic Components ◽  
The Relationship

A theoretical analysis has been done to investigate the static performance of short hydrodynamic journal bearings with a generalized film thickness expression by a sum of Fourier series equation. The hydrodynamic film thickness was written into a summation of an infinite harmonic component of trigonometric function. Reynolds equation with short bearing theory is solved for steady-state operations. In this paper, the steady-state analysis of the generalized hydrodynamic bearing has been done and compared with some typical journal bearings with respect to their harmonic components of film thickness, pressure distribution and load capacity. The relationship between the k-th order harmonic component of the film thickness H0,k and the static pressure component P0,k was established. It was found that the value of P0,k is directly determined not only by the k-th order harmonic component H0,k but also the (k−1)-th order component P0,k−1 indirectly produced by the previous harmonic component H0,k−1.This new investigation method can used to improve the performance of hydrodynamic journal bearings for shape optimization of hydrodynamic journal bearings.

Static Performance Characteristics of Finite-Width Turbulent Journal Bearings with THD Effect

2012 ◽  
Vol 55 (3) ◽  
pp. 302-312 ◽  
Author(s):  
Shiuh-Hwa Shyu ◽  
Wei-Ren Lee ◽  
Sheng-Jii Hsieh ◽  
Shen-Min Liang
Keyword(s):  
Journal Bearings ◽  
Performance Characteristics ◽  
Finite Width ◽  
Static Performance

scholarly journals Analysis of the effect of oil inlet size on the static performance characteristics of non-Newtonian lubricated hole-entry hybrid journal bearings

2021 ◽  
Vol 37 ◽  
pp. 522-531
Author(s):  
Haiyin Cao ◽  
Yu Huang ◽  
Youmin Rong ◽  
Hao Wu ◽  
Minghui Guo
Keyword(s):  
Finite Element Method ◽  
High Speed ◽  
Reynolds Equation ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Power Law Model ◽  
The Finite Element Method ◽  
Solution Strategy ◽  
Nonuniform Mesh ◽  
Static Performance

Abstract In this study, the influence of inlet pocket size on the static performance of non-Newtonian lubricated hole-entry hybrid journal bearings is theoretically analyzed. The oil film of the bearing is discretized into a nonuniform mesh containing the geometric characteristics of the oil inlet pocket, and the inlet pocket is treated as a micro-oil recess. The Reynolds equation is solved by the finite element method based on Galerkin's techniques, and a new solution strategy to solve the recess/pocket pressure is proposed. The power-law model is used to introduce the non-Newtonian effect. The results show that the static performance characteristics of this type of bearing are greatly affected by the pocket size at both zero speed and high speed.

Lubrication of Porous Journal Bearings

1972 ◽  
Vol 94 (1) ◽  
pp. 69-73 ◽  
Author(s):  
C. Cusano
Keyword(s):  
Analytical Solution ◽  
Coefficient Of Friction ◽  
Load Capacity ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Eccentricity Ratio ◽  
Design Variables

An analytical solution for the performance characteristics of finite porous journal bearings is obtained. Results are presented which relate the eccentricity ratio and coefficient of friction as functions of load number for design variables of 0.0001, 0.001, 0.01, and 0.1. The load capacity obtained by using the finite bearing theory is compared to the load capacity obtained by using the short-bearing approximation and the infinite-bearing approximation.

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