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.

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.

Effect of Journal Misalignment on the Oil Film Pressure and Temperature Distribution of 3-Lobe Offset Journal Bearing

2005 ◽  
Author(s):  
S. Strzelecki ◽  
Z. Towarek
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Good Stability ◽  
Rotating Machines ◽  
Film Pressure ◽  
Bearing Design ◽  
Journal Misalignment ◽  
Oil Film Pressure

The design of turbines and compressors operating at the high rotational speeds applies the 3-lobe journal bearings. In many cases the classic 3-lobe journal bearings supporting the rotors, are showing the problem of rotor stability. This problem can be avoided by the application of 3-lobe Offset bearings. This type of bearing fulfils the conditions of reliable bearing design and good stability in the case of high speed rotating machines.

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.

scholarly journals Numerical two-dimensional thermal analysis of the human skin using the multigrid method

2019 ◽  
Vol 42 ◽  
pp. e40992
Author(s):  
Gylles Ricardo Stroher ◽  
Cosmo Damião Santiago
Keyword(s):  
Thermal Analysis ◽  
Steady State ◽  
Temperature Distribution ◽  
Body Temperature ◽  
Multigrid Method ◽  
Medical Diagnostics ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Bioheat Equation ◽  
Average Skin

Heat can be used as an adjuvant treatment of many diseases and also as a powerful tool to help diagnose cancers, with the advantage to be a noninvasive exam. Some tumors may be best diagnosed by evaluating body temperature distribution, for instance, it is observed that local temperatures of the skin over a tumor are higher than the average skin temperature. Certainly, it is expected from medical diagnostics to be, early, fast and very precise. Especially if the health problem is a tumor, it is necessary to know the shape and the size of the cancer. Thermal images can provide further information about the tumor, generally, the thermal diagnostic is made comparing images of the region with a bioheat model. In this context, the present study shows interesting results about the multigrid method applied to solve the Pennes bioheat equation in two dimensions, using a non-stationary and steady state cases for the skin heath and with melanoma. The multigrid method presented itself as an extremely efficient and fast tool to solve the bioheat equation with refined grids that provide good spatial precision.

Investigations of the three-dimensional temperature field of journal bearings considering conjugate heat transfer and cavitation

2019 ◽  
Vol 71 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Qiang Li ◽  
Shuo Zhang ◽  
Yujun Wang ◽  
Wei-Wei Xu ◽  
Zhenbo Wang
Keyword(s):  
Temperature Distribution ◽  
Conjugate Heat Transfer ◽  
Radial Direction ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Temperature Zone ◽  
Content Type ◽  
Higher Temperature

Purpose The growing demand of efficiency and economy has led to a dramatic increase of the operating speed of the journal bearing, with a higher temperature distribution. This paper aims to investigate the three-dimensional temperature distribution of journal bearings. Design/methodology/approach A thermo-hydrodynamic lubrication model of a journal bearing was established based on the full 3D CFD method. A two-sided wall was used to include the conjugate heat transfer effect. The temperature-dependent characteristics of lubrication and cavitation impact were also included. The simulation results well agreed with the experimental results. Based on this method, the three-dimensional temperature distribution was analyzed under different operating conditions. Findings The temperature distribution in the radial direction had a difference. An increase of speed and de-crease of inlet temperature promoted temperature differences in the higher temperature zone and the increasing temperature zone, respectively. However, the inlet pressure had less influence on these differences. The temperature distribution was basically the same at a lower bearing conductivity. As the conductivity increased, the radial temperature difference was increased. Originality/value The temperature distribution in the radial direction was found under different operating conditions, and the present research provides references to understand the three-dimensional temperature distribution of journal bearings.

Oil Film Temperature Distribution of Cylindrical Journal Bearings With Variable Axial Profile

2005 ◽  
Author(s):  
S. Strzelecki ◽  
S. M. Ghoneam ◽  
T. Someya
Keyword(s):  
Temperature Distribution ◽  
Stress Concentration ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Transient Conditions ◽  
Oil Film ◽  
Position Errors ◽  
Mixed Friction ◽  
Axial Profile

Misaligned shaft affects the bearings characteristics and significantly diminishes the range of safe bearing operation and it generates the mixed friction and transient conditions of unstable operation. Misalignment of journal bearing can be caused by position errors too. Journal bearings with. hyperboloidal profile extend the bearing operation range without the stress concentration on the edges of bush and the load can be carried without application of self-aligning bearings.

Thermal Effects in Dynamically Loaded Flexible Journal Bearings

1989 ◽  
Vol 111 (1) ◽  
pp. 49-55 ◽  
Author(s):  
H. Moes ◽  
P. B. Y. Ten Hoeve ◽  
J. Van der Helm
Keyword(s):  
Temperature Distribution ◽  
Viscous Dissipation ◽  
Heat Generation ◽  
Thermal Effects ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Connecting Rod ◽  
Lubricant Flow ◽  
Dynamically Loaded

A method of taking into account the thermal effects when simulating dynamically loaded, flexible, journal bearings on a computer will be introduced. The method is an extension of Van der Tempel’s model for a flexible, short journal bearing under severe dynamic duty, with partial circumferential supply grooves, cavitation and cavitation induced starvation. It incorporates the heat generation due to the viscous dissipation and the cooling due to the axial and circumferential flow of lubricant. The results for the film thicknesses, the lubricant flow, the viscous dissipation and the temperature distribution in two specific connecting-rod bearing configurations will be presented.

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