Elastohydrodynamic Studies of Three-Lobe Journal Bearings with Non-Newtonian Lubricants

1991 ◽  
Vol 205 (6) ◽  
pp. 379-388 ◽  
Author(s):  
K C Goyal ◽  
R Sinhasan
Keyword(s):  
Journal Bearing ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Performance Characteristics ◽  
Continuity Equations ◽  
Viscosity Term ◽  
Elasticity Equations ◽  
Wide Range ◽  
Deformation Coefficient ◽  
Three Dimensional Elasticity

A computer aided elastohydrodynamic study of the three-lobe journal bearing with non-Newtonian lubricants is presented for the static and dynamic performance characteristics. The three-dimensional momentum and continuity equations in cylindrical coordinates governing the flow of Newtonian lubricants in the clearance space of a three-lobe journal bearing have been solved using the finite element method. The non-Newtonian effect is introduced by modifying the viscosity term for the model iteratively. Three-dimensional elasticity equations are solved to obtain deformations in the bearing shell. Static and dynamic performance characteristics are presented for a wide range of values of non-dimensional load, deformation coefficient and non-linearity factor.

A Study of Elastohydrodynamic Lubrication of a Centrally Loaded 120° Arc Partial Bearing in Different Flow Regimes

1983 ◽  
Vol 197 (2) ◽  
pp. 97-108 ◽  
Author(s):  
S C Jain ◽  
R Sinhasan ◽  
D V Singh
Keyword(s):  
Elastic Deformation ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Elastohydrodynamic Lubrication ◽  
Performance Characteristics ◽  
The Finite Element Method ◽  
Elasticity Equations ◽  
Laminar And Turbulent Flow ◽  
Deformation Coefficient ◽  
Three Dimensional Elasticity

The elastic deformation of the bearing liner is considered in determining the static and dynamic performance characteristics of the centrally loaded 120° arc bearing for eccentricity ratio up to 0.8 and mean Reynolds number up to 7500. Using the finite element method, the pressure distribution in the fluid film and the elastic deformation in the bearing shell are obtained by solving the Reynolds equation and the three-dimensional elasticity equations iteratively. The performance characteristics of the bearing are computed for different values of the deformation coefficient which is a measure of the flexibility of the bearing shell. In addition, some results are also reported for laminar and turbulent flow conditions treating viscosity as a function of pressure.

Influence of Wear on the Performance of Multirecess Hydrostatic Journal Bearing Operating With Micropolar Lubricant

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
E. Rajasekhar Nicodemus ◽  
Satish C. Sharma
Keyword(s):  
Journal Bearing ◽  
Dynamic Performance ◽  
Flow Equation ◽  
Performance Characteristics ◽  
Wear Depth ◽  
Damping Coefficients ◽  
Load Line ◽  
Wide Range ◽  
Load Arrangement ◽  
Stiffness And Damping

The objective of the present work is to study theoretically the influence of wear on the performance of four-pocket capillary-compensated hydrostatic journal bearing operating with micropolar lubricant. In the present study, the lubricant containing additives and contaminants is modeled as micropolar fluid. The modified Reynolds equation for micropolar lubricant is solved using finite element method along with capillary restrictor flow equation as a constraint together with appropriate boundary conditions. The performance characteristics of a capillary-compensated four-pocket worn hydrostatic journal bearing operating with micropolar lubricant have been presented for a wide range of values of nondimensional external load, wear depth parameter, and micropolar parameters. The simulated results have also been presented for two different loading arrangements. In arrangement I, the load line acts through centers of the pockets, whereas in arrangement II, the load line bisects the land between two pockets. The simulated results suggest that a bearing lubricated with lubricant having higher micropolar effect has better static and dynamic performance characteristics as compared with Newtonian lubricant but the bearing lubricated with lubricant having higher micropolar effect is predominantly affected by the wear vis a vis static characteristics parameters as compared with Newtonian lubricant for both loading arrangements. However, in the case of stiffness and damping coefficients, loading arrangement II shows a significant higher enhancement in the value of direct stiffness and damping coefficients in z-direction due to micropolar effect as compared with load arrangement I. And also, the effect of wear on stiffness and damping coefficients in z-direction for bearing operating with micropolar lubricant is of same order as Newtonian lubricant for the loading arrangement II. A similar behavior is observed for the case of stiffness and damping coefficients in x-direction for loading arrangement I.

Solution of the Elastohydrodynamic Finite Journal Bearing Problem

1973 ◽  
Vol 95 (3) ◽  
pp. 342-351 ◽  
Author(s):  
K. P. Oh ◽  
K. H. Huebner
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Solution Procedure ◽  
Iteration Scheme ◽  
Bearing Material ◽  
Constant Property ◽  
Elasticity Equations ◽  
Minimum Film Thickness ◽  
Three Dimensional Elasticity

Finite-element techniques are applied to solve the elastohydrodynamic finite journal bearing problem. Reynolds’ equation for the fluid film and the three-dimensional elasticity equations for the bearing housing are solved simultaneously using a unique iteration scheme. The analysis yields the pressure distribution and the displacement distribution which satisfy the elastohydrodynamic requirements of realistic three-dimensional bearing geometries. From these distributions, important information such as the stresses in the bearing material and the minimum film thickness in the lubricant can be calculated. In the calculations it is assumed that the bearing operates with a constant-property lubricant and a linearly elastic bearing material. The solution procedure is applied to a typical problem and numerical results are presented.

Influence of Semi Cone Angle on Performance of a Non-Recessed Hybrid Conical Journal Bearing

2015 ◽  
Author(s):  
Prashant G. Khakse ◽  
Vikas M. Phalle ◽  
S. S. Mantha
Keyword(s):  
Journal Bearing ◽  
Dynamic Performance ◽  
Cone Angle ◽  
Performance Characteristics ◽  
Fluid Film ◽  
Damping Coefficient ◽  
Lubricant Flow ◽  
Wide Range ◽  
Speed Effect ◽  
Film Stiffness

The present paper describes the analytical approach to find the static and dynamic performance characteristics of a newly configured non-recess hole-entry hybrid conical journal bearing, considering the speed effect of journal compensated with capillary restrictors. Capillary restrictors are placed in the holes which are drilled over the periphery of the conical journal bearing. These holes are placed at an angle of 30 degree in the circumferential direction. The modified Reynolds equation which governs the lubricant flow in the clearance space of journal and bearing is solved by using Finite Element Method (FEM). The performance characteristics for the non-recess hole-entry hybrid conical journal bearing have been shown for wide range of restrictor design parameter (C̄s2 = 0.02–0.1) in terms of bearing flow, direct fluid film stiffness and direct fluid film damping coefficient for different semi cone angles γ = 5deg, 10 deg, 20 deg and 30 deg. The results obtained from the simulation indicates that the non-recess hole-entry hybrid conical journal bearing depicts important performance characteristics for bearing flow (Q) and fluid film stiffness which may be useful for bearing designer. However, the non-recess hole-entry hydrostatic conical journal bearing shows desirable performance for fluid film damping coefficient.

Analytical and 3D Finite Element Study of the Deflection of an Elastic Cantilever Bilayer Plate

2010 ◽  
Vol 78 (1) ◽  
Author(s):  
M. Chekchaki ◽  
V. Lazarus ◽  
J. Frelat
Keyword(s):  
Thin Films ◽  
Finite Element ◽  
Three Dimensional ◽  
Analytical Formula ◽  
Mechanical Stresses ◽  
Linear Elastic ◽  
Wide Range ◽  
Finite Element Calculations ◽  
Analytical Formulas ◽  
Three Dimensional Elasticity

The mechanical system considered is a bilayer cantilever plate. The substrate and the film are linear elastic. The film is subjected to isotropic uniform prestresses due for instance to volume variation associated with cooling, heating, or drying. This loading yields deflection of the plate. We recall Stoney’s analytical formula linking the total mechanical stresses to this deflection. We also derive a relationship between the prestresses and the deflection. We relax Stoney’s assumption of very thin films. The analytical formulas are derived by assuming that the stress and curvature states are uniform and biaxial. To quantify the validity of these assumptions, finite element calculations of the three-dimensional elasticity problem are performed for a wide range of plate geometries, Young’s and Poisson’s moduli. One purpose is to help any user of the formulas to estimate their accuracy. In particular, we show that for very thin films, both formulas written either on the total mechanical stresses or on the prestresses, are equivalent and accurate. The error associated with the misfit between our theorical study and numerical results are also presented. For thicker films, the observed deflection is satisfactorily reproduced by the expression involving the prestresses and not the total mechanical stresses.

A general evaluation method for the diabatic journal bearing

1974 ◽  
Vol 336 (1606) ◽  
pp. 307-325 ◽  
Keyword(s):  
Evaluation Method ◽  
Journal Bearing ◽  
Design Method ◽  
Three Dimensional ◽  
Algebraic Equations ◽  
Mixing Conditions ◽  
General Evaluation ◽  
Wide Range ◽  
Energy Equations ◽  
Independent Parameters

A design method is described for the steadily loaded, full journal bearing. This is presented as a non-iterative set of algebraic equations, where a dependent bearing parameter, e. g. eccentricity or power-loss, is predicted in terms of known independent parameters which include bearing geometry, running conditions and oil characteristics. The method is developed from a regression analysis of accurately computed, fully thermohydrodynamic, solutions for the bearing. These solutions are generated by simultaneously solving the Reynolds and energy equations in the oil film, the Laplace equation in the bearing material and the oil-mixing conditions at inlet. A quasi three-dimensional finite-difference technique is used. Both the particular solutions and the predictions of the design method compare favourably with a wide range of experimental data, the latter showing an improvement in accuracy and economy on existing design methods.

Elasticity solution for thick laminated anisotropic cylindrical panels under dynamic load

2002 ◽  
Vol 216 (3) ◽  
pp. 315-322 ◽  
Author(s):  
A Alibiglu ◽  
M Shakeri ◽  
M R Eslami
Keyword(s):  
Differential Equations ◽  
Dynamic Load ◽  
Three Dimensional ◽  
Variable Coefficients ◽  
Cylindrical Panel ◽  
Great Length ◽  
Elasticity Equations ◽  
Shell Panel ◽  
Asymmetric Load ◽  
Three Dimensional Elasticity

The dynamic response of an axisymmetric arbitrary laminated anisotropic cylindrical panel subjected to asymmetric load is studied on the basis of three-dimensional elasticity equations. The shell panel has a great length and is simply supported at both edges. The highly coupled partial differential equations (PDEs) are reduced to ordinary differential equations (ODEs) with variable coefficients by means of trigonometric function expansion in circumferential directions. The resulting OPEs are solved by Galerkin's finite element method. Numerical examples are presented for 45°/-45° and 45°/-45°/45° laminations under dynamic load. Finally, the results are compared with published results.

Computational Fluid Dynamics Based Mixing Prediction for Tilt Pad Journal Bearing TEHD Modeling—Part I: TEHD-CFD Model Validation and Improvements

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Jongin Yang ◽  
Alan Palazzolo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Journal Bearing ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Prediction Method ◽  
Conventional Approach ◽  
Machine Learning Techniques ◽  
Prediction Errors ◽  
Cfd Model

Abstract The core contributions of Part I (1) present a computational fluid dynamics (CFD)-based approach for tilting pad journal bearing (TPJB) modeling including thermo-elasto hydrodynamic (TEHD) effects with multi-mode pad flexibility, (2) validate the model by comparison with experimental work, and (3) investigate the limitations of the conventional approach by contrasting it with the new approach. The modeling technique is advanced from the author’s previous work by including pad flexibility. The results demonstrate that the conventional approach of disregarding the three-dimensional flow physics between pads (BP) can generate significantly different pressure, temperature, heat flux, dynamic viscosity, and film thickness distributions, relative to the high-fidelity CFD model. The uncertainty of the assumed mixing coefficient (MC) may be a serious weakness when using a conventional, TPJB Reynolds model, leading to prediction errors in static and dynamic performance. The advanced mixing prediction method for “BP” thermal flow developed in Part I will be implemented with machine learning techniques in Part II to provide a means to enhance the accuracy of conventional Reynolds based TPJB models.

Analysis of Multirecess Hydrostatic Journal Bearing Operating With Micropolar Lubricant

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Suresh Verma ◽  
Vijay Kumar ◽  
K. D. Gupta
Keyword(s):  
Reynolds Equation ◽  
Theoretical Study ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Constant Flow ◽  
The Finite Element Method ◽  
Lubricant Flow ◽  
Wide Range ◽  
Flow Valve

This paper presents a theoretical study of the performance characteristics of a constant flow valve compensated multirecess hydrostatic journal bearings operating with micropolar lubricant. The finite element method and iterative procedure have been used to solve the modified Reynolds equation governing the micropolar lubricant flow in the bearing. The performance characteristics are presented for a wide range of nondimensional load, lubricant flow, and micropolar parameters. It has been observed that the micropolar parameters significantly influence the performance characteristics of the bearing.

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