Thermoelastohydrodynamic behavior of misaligned plain journal bearings

2013 ◽  
Vol 227 (11) ◽  
pp. 2582-2599 ◽  
Author(s):  
ZS Zhang ◽  
XD Dai ◽  
YB Xie
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Misalignment Angle ◽  
Synthetic Solution ◽  
Simulation Results ◽  
Generalized Reynolds Equation

Under severe operating conditions, the thermal effects and various deformations play an important role in determining the performance of misaligned plain journal bearings. However, the thermal effects and various deformations are rarely considered simultaneously in most studies on the misaligned plain journal bearings. In this article, a comprehensive thermoelastohydrodynamic model of the misaligned plain journal bearings is developed that involves the synthetic solution of the generalized Reynolds equation, three-dimensional energy equation, and heat conduction equations of the solids. Based on this model, series of simulation results are provided to examine the influence of the thermal effects and deformations on the behavior of the misaligned plain journal bearings. In addition, the comparisons between the thermohydrodynamic and complete thermoelastohydrodynamic model are also presented for different misalignment angle and magnitude. Results show that the thermal effects and various deformations should not be ignored because of their significant influence on the film thickness, film pressure as well as other bearings characteristics.

Analysis of Thermal Effects in Hydrodynamic Bearings

1986 ◽  
Vol 108 (2) ◽  
pp. 219-224 ◽  
Author(s):  
R. Boncompain ◽  
M. Fillon ◽  
J. Frene
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Effects ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Heat Transfer Equation ◽  
Reversed Flow ◽  
Theoretical Results ◽  
Generalized Reynolds Equation ◽  
Good Agreement

A general THD theory and a comparison between theoretical and experimental results are presented. The generalized Reynolds equation, the energy equation in the film, and the heat transfer equation in the bush and the shaft are solved simultaneously. The cavitation in the film, the lubricant recirculation, and the reversed flow at the inlet are taken into account. In addition, the thermoelastic deformations are also calculated in order to define the film thickness. Good agreement is found between experimental data and theoretical results which include thermoelastic displacements of both the shaft and the bush.

Hydrodynamic Thrust Bearings: Theory and Experiment

1991 ◽  
Vol 113 (3) ◽  
pp. 633-638 ◽  
Author(s):  
A. K. Tieu
Keyword(s):  
Thermal Effects ◽  
High Speed ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Thrust Bearing ◽  
Experimental Studies ◽  
Test Rig ◽  
Oil Viscosity ◽  
Thrust Bearings ◽  
Generalized Reynolds Equation

In this paper results from experimental studies and computer simulation of hydro-dynamic tilting thrust bearings are presented. The bearing performance in terms of outlet film thickness, friction coefficient, and bearing temperature was measured in a high speed thrust bearing test rig. The numerical simulation involves the solution of the generalized Reynolds equation and the energy equation, which considers thermal effects on the oil viscosity and the squeezing of the oil film.

Bifurcation Analysis of Self-Acting Gas Journal Bearings

2001 ◽  
Vol 123 (4) ◽  
pp. 755-767 ◽  
Author(s):  
Cheng-Chi Wang ◽  
Cha’o-Ku`ang Chen
Keyword(s):  
Dynamic Behavior ◽  
Reynolds Equation ◽  
Rotational Velocity ◽  
Power Spectra ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Finite Differences Method ◽  
Subharmonic Response ◽  
Rotor Center ◽  
Rotor Mass

This paper studies the bifurcation of a rigid rotor supported by a gas film bearing. A time-dependent mathematical model for gas journal bearings is presented. The finite differences method and the Successive Over Relation (S.O.R) method are employed to solve the Reynolds’ equation. The system state trajectory, Poincare´ maps, power spectra, and bifurcation diagrams are used to analyze the dynamic behavior of the rotor center in the horizontal and vertical directions under different operating conditions. The analysis shows how the existence of a complex dynamic behavior comprising periodic and subharmonic response of the rotor center. This paper shows how the dynamic behavior of this type of system varies with changes in rotor mass and rotational velocity. The results of this study contribute to a further understanding of the nonlinear dynamics of gas film rotor-bearing systems.

scholarly journals Run-Up Simulation of a Semi-Floating Ring Supported Turbocharger Rotor Considering Thrust Bearing and Mass-Conserving Cavitation

Lubricants ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 44
Author(s):  
Christian Ziese ◽  
Cornelius Irmscher ◽  
Steffen Nitzschke ◽  
Christian Daniel ◽  
Elmar Woschke
Keyword(s):  
Reynolds Equation ◽  
Energy Equation ◽  
Thrust Bearing ◽  
Three Dimensional ◽  
Reliable Prediction ◽  
Two Phase ◽  
Hydrodynamic Bearings ◽  
Thrust Bearings ◽  
Run Up ◽  
The Impact

The vibration behaviour of turbocharger rotors is influenced by the acting loads as well as by the type and arrangement of the hydrodynamic bearings and their operating condition. Due to the highly non-linear bearing behaviour, lubricant film-induced excitations can occur, which lead to sub-synchronous rotor vibrations. A significant impact on the oscillation behaviour is attributed to the pressure distribution in the hydrodynamic bearings, which is influenced by the thermo-hydrodynamic conditions and the occurrence of outgassing processes. This contribution investigates the vibration behaviour of a floating ring supported turbocharger rotor. For detailed modelling of the bearings, the Reynolds equation with mass-conserving cavitation, the three-dimensional energy equation and the heat conduction equation are solved. To examine the impact of outgassing processes and thrust bearing on the occurrence of sub-synchronous rotor vibrations separately, a variation of the bearing model is made. This includes run-up simulations considering or neglecting thrust bearings and two-phase flow in the lubrication gap. It is shown that, for a reliable prediction of sub-synchronous vibrations, both the modelling of outgassing processes in hydrodynamic bearings and the consideration of thrust bearing are necessary.

Investigation of the micropolar lubricant and thermal effects in the slot entry hybrid journal bearings

2017 ◽  
Vol 232 (11) ◽  
pp. 2103-2116 ◽  
Author(s):  
Pankaj Khatak ◽  
HC Garg
Keyword(s):  
Performance Analysis ◽  
Present Article ◽  
Thermal Effects ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Reliable Performance ◽  
Isothermal Characteristics

The present article studies the combined influence of the micropolar lubricant and thermal effects in the slot entry hybrid journal bearings. Bearing performance characteristics are computed by the concurrent solution of modified Reynolds, three-dimensional micropolar energy, and three-dimensional conduction equations. Thermohydrostatic characteristics of the slot entry hybrid journal bearings have been studied vis-à-vis isothermal characteristics. The results obtained numerically indicate that isoviscous assumption of the lubricant is incorrect and the bearing performance is significantly affected by the increase in temperature. Hence, it is essential to consider the thermal effects for the bearings operating with the micropolar lubricant for reliable performance analysis of the bearings.

Influence of geometric parameters and operating conditions on the thermohydrodynamic behaviour of plain journal bearings

2000 ◽  
Vol 214 (5) ◽  
pp. 445-457 ◽  
Author(s):  
I Pierre ◽  
M Fillon
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Thermal Dissipation ◽  
Radial Clearance ◽  
Geometric Factors ◽  
Essential Components ◽  
Mass Flowrate

Hydrodynamic journal bearings are essential components of high-speed machinery. In severe operating conditions, the thermal dissipation is not a negligible phenomenon. Therefore, a three-dimensional thermohydrodynamic (THD) analysis has been developed that includes lubricant rupture and re-formation phenomena by conserving the mass flowrate. Then, the predictions obtained with the proposed numerical model are validated by comparison with the measurements reported in the literature. The effects of various geometric factors (length, diameter and radial clearance) and operating conditions (rotational speed, applied load and lubricant) on the journal bearing behaviour are analysed and discussed in order to inform bearing designers. Thus, it can be predicted that the bearing performance obtained highly depends on operating conditions and geometric configuration.

scholarly journals Study on the Effect of the Three-Dimensional Electrode in Degradation of Methylene Blue by Lithium Modified Rectorite

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jian Huang ◽  
Yin’an Ming ◽  
Ying Du ◽  
Yingru Wang ◽  
Ci’en Wang
Keyword(s):  
Methylene Blue ◽  
Electrical Property ◽  
Adsorption Property ◽  
Low Cost ◽  
Three Dimensional ◽  
Cell Voltage ◽  
Operating Conditions ◽  
The Novel ◽  
Synthetic Solution ◽  
Series Of Experiments

This study presents the electrochemical degradation of methylene blue (MB) wastewater in a synthetic solution using three-dimensional particle electrodes. The novel particle electrodes were fabricated in this work using the lithium modified rectorite (Li-REC). The adsorption property of the fabricated particle electrodes was studied in a series of experiments. The optimum electrochemical operating conditions of plate distance, cell voltage, and concentration of electrolyte were 2 cm, 9 V, and 0.06 mol L−1, respectively. It was also found that microwave irradiation can effectively improve the adsorption property and electrical property of the fabricated electrodes. In addition, the scanning electron microscope (SEM) of the fabricated electrodes was investigated. The experimental results revealed the order of adsorption property and electrical property of the fabricated electrodes. So, fabricated electrodes are not only of low cost and mass produced, but also efficient to achieve decolorization of MB solution.

Numerical Simulation and Stereo PIV Test of Inner Flow in a Double Blades Pump

2011 ◽  
Author(s):  
Kai Wang ◽  
Houlin Liu ◽  
Shouqi Yuan ◽  
Minggao Tan ◽  
Yong Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Velocity Field ◽  
Cfd Simulation ◽  
Research Work ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Absolute Velocity ◽  
Operation Condition ◽  
Test Technique ◽  
Simulation Results

A double blades pump is widely used in sewage treatment industry, while at present the research on the internal flow characteristics of the double blades pump is very few. So, the CFD technology and the stereo PIV test technique are applied to study the inner flow in a double blades pump whose specific speed is 110.9. The commercial code FLUENT is used to simulate the inner flow in the double blades pump at 0.6Qd, 0.8Qd, 1.0Qd, 1.2Qd and 1.4Qd. The RNG k-ε turbulence model and SIMPLEC algorithm are used in FLUENT. According to the results of the three-dimensional steady numerical simulation, the distributions of velocity field in the impeller are obtained at the five different operating conditions. The analysis of the numerical simulation results shows that there is an obvious vortex in the impeller passage at off-design conditions. But the number, location and area of the vortex are different from each operation condition. In order to validate CFD simulation results, the stereo PIV is used to test the absolute velocity distribution in the double blades pump at Jiangsu University. The distributions of three-dimensional absolute velocity field at the above five different operating conditions are obtained by the PIV test, and the measured results are compared with the CFD simulation results. The comparison indicates that there are vortexes in impeller passages of the double blades pump under the five operating conditions. But as to the area of the vortex and the relative velocity values of the vortex core, there are some differences between the experiment results and the numerical simulation results. The research work can be applied to instruct the hydraulic design of double blades pumps.

A Contribution to the Analysis of the Thermo-Hydrodynamic Lubrication of Porous Self-Lubricating Journal Bearings

2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Porous Matrix ◽  
Journal Bearings ◽  
Governing Equations ◽  
Hydrodynamic Analysis ◽  
Result Show

In this work the influence of thermal effects on the performance of a finite porous journal bearing has been investigated using a thermo-hydrodynamic analysis. The Reynolds equation of thin viscous films is modified taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The governing equations were solved numerically using the finite difference approach. Obtained result show a reduction in the performance of journal bearings when the thermal effects are accounted for and, this reduction is greater when the load capacity is significant.

On the granular lubrication theory

2005 ◽  
Vol 461 (2062) ◽  
pp. 3255-3278 ◽  
Author(s):  
J.Y Jang ◽  
M.M Khonsari
Keyword(s):  
Granular Material ◽  
Reynolds Equation ◽  
Three Dimensional ◽  
Lubrication Theory ◽  
Slider Bearing ◽  
Governing Equations ◽  
Three Dimensional Flow ◽  
Generation Capacity ◽  
Side Flow ◽  
Generalized Reynolds Equation

The governing equations for the flow of a granular material within the context of the lubrication theory are derived. The resulting analysis gives a generalized Reynolds equation that predicts the pressure generation capacity in a bearing with consideration of side flow. A series of simulations are presented that characterize the three-dimensional flow behaviour of powder in a slider bearing.

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