Paper 6: A Thermohydrodynamic Analysis of Journal Bearings

1966 ◽  
Vol 181 (15) ◽  
pp. 117-126 ◽  
Author(s):  
D. Dowson ◽  
C. N. March
Keyword(s):  
Heat Conduction ◽  
Journal Bearing ◽  
Journal Bearings ◽  
General Nature ◽  
Two Dimensional ◽  
Approximate Representation ◽  
Full Account ◽  
Design Procedures ◽  
Experimental Findings ◽  
Energy Equations

A thermohydrodynamic analysis is discussed which takes account of the general nature of the experimental observations in work which forms part of a programme of research designed to develop an improved understanding of better design procedures for journal bearings. The analysis considers compatible solutions of the Reynolds, energy, and heat conduction equations for two-dimensional conditions. It is shown that the solutions are in reasonable agreement with experimental findings. The two-dimensional solutions of the Reynolds and energy equations take full account of the variation of lubricant properties along and across the film. A very simple and approximate representation is used to estimate the temperature distribution in the bush, but the solutions present a reasonable estimate of bush and shaft temperatures. The ‘thermohydrodynamic’ or ‘heat conduction’ solution to journal bearing problems will provide intermediate, and it is hoped more realistic, results between the extreme ‘isothermal’ and ‘adiabatic’ conditions.

Partial Journal Bearing Performance in the Laminar Regime

1975 ◽  
Vol 97 (1) ◽  
pp. 94-100 ◽  
Author(s):  
T. S. Yu ◽  
A. Z. Szevi
Keyword(s):  
Heat Conduction ◽  
Radial Direction ◽  
Journal Bearing ◽  
Two Dimensional ◽  
Approximate Analysis ◽  
Laminar Regime ◽  
Design Charts ◽  
Numerical Iteration ◽  
Equation Of Heat Conduction ◽  
Energy Equations

In this approximate analysis of laminar journal bearing operations both the momentum and the energy equations are two dimensional, the shaft operates at a constant temperature and the bearing conducts heat in the radial direction only. Via the last of these assumptions, the equation of heat conduction is eliminated from consideration. The remaining equations are solved by a numerical iteration method. A parametric study of therohydrodynamic journal bearing operations is performed and design charts are given for a 100 deg arc bearing.

Thermohydrodynamic Analysis of Solid-Liquid Lubricated Journal Bearings

1988 ◽  
Vol 110 (2) ◽  
pp. 367-374 ◽  
Author(s):  
M. M. Khonsari ◽  
V. Esfahanian
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Solid Particles ◽  
Governing Equations ◽  
Transfer Processes ◽  
Flow And Heat Transfer ◽  
Experimental Findings ◽  
Solid Liquid ◽  
General Computer Program ◽  
Good Agreement

Thermohydrodynamic theory is extended to include the effect of solid particles in hydrodynamically lubricated journal bearings. Appropriate governing equations and boundary conditions are derived for the fluid flow and heat transfer processes taking place in a finite journal bearing. A general computer program is developed to numerically solve the governing equations. Results are provided for biphase lubricants containing oil with molybdenum disulfide and polytetrafluoroethylene particles. The computational results are in good agreement with experimental findings. The results indicate that the bearing temperature field is affected significantly by the presence of particles in oil. Moreover, it is found that inclusion of particles in the lubricant results in a higher coefficient of friction in the mid-range of the Sommerfeld number compared to that of the clean oil.

Thermoelastic influences in journal bearing lubrication

1986 ◽  
Vol 403 (1824) ◽  
pp. 111-134 ◽  
Keyword(s):  
Film Thickness ◽  
Theoretical Investigation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Thermal Distortion ◽  
Two Dimensional ◽  
Thickness Increase ◽  
Minimum Film Thickness ◽  
The Stability

A theoretical investigation is made to study the way in which thermal distortion of bearing components modifies the characteristics of journal bearings. The thermoelastic treatment developed is two-dimensional and incorporates an existing thermohydrodynamic analysis. It is applied to circular and partial arc bearings for a range of parametric groups governing the bearing operation. The results show that for a fixed journal position, the effect of thermal distortion is to reduce the minimum film thickness, increase the load capacity, increase the peak temperatures and pressures, and also to enhance considerably the stability of the bearing. The effects are more marked for larger oil-lubricated bearings and higher speeds of operation and it is suggested that discrepancies observed between experimental results and existing theory could be largely explained by this phenomenon.

Research on Energy Equation of Lubrication Model on Large-Scale Journal Bearing System

2010 ◽  
Vol 145 ◽  
pp. 139-144
Author(s):  
Jian Mei Wang ◽  
Qing Xue Huang ◽  
Jian Feng Kang ◽  
Yang Fan
Keyword(s):  
Service Life ◽  
Large Scale ◽  
Energy Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Journal Bearings ◽  
Calculation Results ◽  
Major Factors ◽  
Energy Equations ◽  
Bearing System

To prolong the service life of large-scale journal bearings, the major factors that have influences on bearing performances should be taken into account. By consideration of the variations of viscosity and density with pressure and temperature, a more thorough thermo-hydrodynamic lubrication model was established. With designation of variables with nondimensional parameters, a series of equations were nondimensionied, and the corresponding energy equations at different oil-film layers and boundaries were obtained respectively according to proper difference formats, and then solved by the integration of Finite Difference Method (FDM) with Boundary Element Method (BEM). Calculation results have proved that such complete mathematical model could provide great theoretical guide meaning to improve the lubrication performances and to prolong the service life of contact components of heavy journal bearings.

The Analysis of Thermal Effects in a Full Journal Bearing

1970 ◽  
Vol 92 (4) ◽  
pp. 578-587 ◽  
Author(s):  
H. McCallion ◽  
F. Yousif ◽  
T. Lloyd
Keyword(s):  
Thermal Effects ◽  
Energy Equation ◽  
Journal Bearing ◽  
Numerical Techniques ◽  
Temperature Distributions ◽  
Simplified Method ◽  
Experimental Findings ◽  
Energy Equations ◽  
Steady Load ◽  
Adiabatic Case

By means of numerical techniques, the behavior of a journal bearing of finite length running under steady load, including thermal effects, is investigated with reference to the two simpler models: the “isothermal” and the “adiabatic” cases. Different bearing operating parameters are obtained, which in the latter case are evaluated from the pressure and temperature distributions obtained from the simultaneous solution of the Reynolds and Energy equations. A simplified method, which uncouples the Reynolds and the Energy equations in the oil by neglecting all the pressure terms in the energy equation, is discussed and compared with the more exact numerical method of solving the two equations simultaneously. The case of heat being conducted through metal surfaces is described, with the assumption of zero net heat flow to the journal. In order to shorten the calculations, the uncoupling technique investigated in the adiabatic case is again used and the results obtained are compared with experimental findings.

Thermal Analysis of Noncircular Bearings

1996 ◽  
Vol 118 (1) ◽  
pp. 246-254 ◽  
Author(s):  
A. Hussain ◽  
K. Mistry ◽  
S. Biswas ◽  
K. Athre
Keyword(s):  
Thermal Analysis ◽  
Temperature Distribution ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Two Dimensional

The present work is on prediction of temperature distribution in noncircular journal bearings and the surrounding solids. Three forms are studied, viz. two-lobe, elliptical and orthogonally displaced bearings. For comparison purposes, a circular bearing with two different groove locations is analyzed. The investigation includes the effects of recirculation and oil mixing at the grooves. The cavitation zone has also been investigated. The work is based on a two-dimensional treatment following McCallion’s approach. The results are presented for various geometries of journal bearing configuration, including the conventional circular bearing.

Effect of Viscosity on Gaseous Flow in a Micro-Nozzle

2004 ◽  
Author(s):  
Shintaro Murakami ◽  
Yutaka Asako
Keyword(s):  
Heat Conduction ◽  
Analytical Solutions ◽  
Two Dimensional ◽  
Arbitrary Lagrangian Eulerian ◽  
Numerical Computations ◽  
Gaseous Flow ◽  
One Dimensional ◽  
Micro Nozzle ◽  
Wide Range ◽  
Energy Equations

Two-dimensional compressible momentum and energy equations are solved numerically to obtain the effect of viscosity on gaseous flow in a micro converging-diverging nozzle. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The numerical computations were performed for a wide range of the diverging angle and throat height and for no-heat conduction flow. The results are compared with one-dimensional analytical solutions for flow in a conventional sized nozzle and the effects of the viscosity on gaseous flow in the micro-nozzle are discussed.

First Paper: An Analytical Study of the Tilting Pad Gas Lubricated Journal Bearing

1966 ◽  
Vol 181 (1) ◽  
pp. 293-300 ◽  
Author(s):  
G. Pitts
Keyword(s):  
Analytical Solution ◽  
Analytical Study ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Diameter Ratio ◽  
Sample Design ◽  
Tilting Pad ◽  
Experimental Findings ◽  
Single Set

Presented in this paper is an analytical method of producing design curves for tilting pad gas journal bearings, with dimensionless parameters chosen in such a way that a single set of curves may be used for any size of bearing with any length to diameter ratio. An analytical solution to the compressible Reynolds equation, based on the linearization by Ausman, is presented in detail. Comparisons are made between the analytical results, numerical results, and experimental findings on the author's rig at Southampton University. Included in the paper is a sample design curve, together with equations for constructing additional curves. The author concludes by briefly outlining his proposed extension of this work.

Thermohydrodynamic Analysis of Journal Bearings Considering Cavitation and Reverse Flow

1988 ◽  
Vol 110 (3) ◽  
pp. 439-447 ◽  
Author(s):  
H. H. Ott ◽  
G. Paradissiadis
Keyword(s):  
Boundary Condition ◽  
Theoretical Model ◽  
Energy Equation ◽  
Journal Bearing ◽  
Reverse Flow ◽  
Iterative Solution ◽  
Journal Bearings ◽  
Flow Area ◽  
Hydrodynamic Journal Bearing ◽  
Energy Equations

The flow field of a hydrodynamic journal bearing is calculated by the iterative solution of the system of Reynolds and energy equations. In the case of reverse flow at the film inlet, the temperature profile there can not be prescribed as a boundary condition but has to be determined from the flow in the film. This is achieved by a separate integration of the energy equation in the reverse flow area. The flow in the cavitation regions is approximated by a theoretical model leading to a form of the energy equation similar to that for pressure regions, thus enabling the integration of the energy equation over the whole film.

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