CFD Analysis of Hydrodynamic Pressure Distribution in Non-Newtonian Oil in Journal Bearing Lubrication Gap

2015 ◽  
Vol 220-221 ◽  
pp. 37-42 ◽  
Author(s):  
Adam Czaban
Keyword(s):  
Shear Stress ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Hydrodynamic Pressure ◽  
Journal Bearings ◽  
Lubricating Oil ◽  
Cfd Analysis ◽  
Relationship Power ◽  
Lift Capacity ◽  
Relative Eccentricity

This paper presents the results of CFD analysis of the hydrodynamic pressure distribution in slide journal bearings lubricated by non-Newtonian oil. It was assumed that the oil shear stress varies from shear rate according to the Ostwald–de Waele relationship (power law lubricant). The comparison was related to bearings differences only in properties of lubricating oil – Newtonian and non-Newtonian properties; other parameters for both in each case were the same. The Tables show relative decrease of the maximum hydrodynamic pressure value and bearing lift capacity according to the bearing lubricated with Newtonian oil, for different values of bearing relative eccentricity.

Experimentally study of dynamic pressure distribution and oil film forces in journal bearing using ElectroMechanical Film sensor array

2019 ◽  
Vol 234 (4) ◽  
pp. 903-913
Author(s):  
Changmin Chen ◽  
Jianping Jing ◽  
Jiqing Cong ◽  
Chao Ji
Keyword(s):  
Pressure Distribution ◽  
Sensor Array ◽  
Journal Bearing ◽  
Dynamic Pressure ◽  
Vertical Direction ◽  
Journal Bearings ◽  
Film Sensor ◽  
Film Pressure ◽  
Oil Film ◽  
Oil Film Pressure

The acquisition of the oil film pressure and forces on the bearing pads through experimentation is crucial to understanding the characteristics of journal bearing. Lots of efforts had been taken in film pressure measurement, and the pressure was obtained at specified position on the bearing pads. However, due to the space and structure constraint, merely very limited number of the point pressure can be obtained with traditional sensors and acquiring the detail pressure field on whole bearing pad surface is still an open challenge. In this paper, a method based on thin-film sensors technique is proposed and employed to measure the pressure distribution and oil film forces of journal bearings. The measurement is conducted on a cylindrical journal bearing with two axial grooves, and ElectroMechanical Film sensor arrays are designed and laid on the surface of the bearing pads. The oil film pressure is acquired at up to 32 measurement points in total along the bearing pads in both circumference and axial directions. The pressure distribution in a wide rotation speed range is obtained successfully by using fitting algorithm. Furthermore, the oil film forces on horizon and vertical direction are obtained through the integration of the measured pressure filed. The test results prove that it is feasible to measure the oil pressure filed of journal bearings using ElectroMechanical Film piezo-film sensor array.

scholarly journals Study on the performance of journal bearings in different lubricants by CFD and FSI method with thermal effect and cavitation

2018 ◽  
Vol 249 ◽  
pp. 03006 ◽  
Author(s):  
Hulin Li ◽  
Yanzhen Wang ◽  
Ning Zhong ◽  
Yonghong Chen ◽  
Zhongwei Yin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thermal Effect ◽  
Journal Bearing ◽  
Fluid Structure Interaction ◽  
Journal Bearings ◽  
Lubricating Oil ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Load Carrying

This paper used a new transient computational fluid dynamics and fluid–structure interaction method to investigate the journal bearing performance with the effect of thermal and cavitation, to reveal the performance of journal bearing in different lubricants and to provide substitution references for bearings in different lubricants. Considering thermal effect, elastic deformation and cavitation, a detailed discussion was conducted to show the performance of plain journal bearings lubricated by water, seawater, and lubricating oil by computational fluid dynamics (CFD) and fluid structure interaction (FSI) method. And the results in this work are compared with the published results. The variation of dimensionless load carrying capacity, maximum film pressure and temperature with eccentricity ratio are presented, which can provide reference for the design of bearings. Furthermore, a diagram is presented for journal bearings with different diameter, length-diameter ratio and lubricants, which can be used as a reference for the equivalent substitutions of bearings. The present research provides references as to the design of bearings and the substitutions of bearings by different lubricants.

Analysis of Single-Grooved Slider and Journal Bearing With Partial Slip Surface

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
T. V. V. L. N. Rao
Keyword(s):  
Shear Stress ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Slip Surface ◽  
Partial Slip ◽  
Maximum Pressure ◽  
Slider Bearing ◽  
Slip Coefficient ◽  
One Dimensional ◽  
Slip Region

In this paper, pressure and shear stress are derived under steady state using one-dimensional analysis of the single-grooved slider bearing and journal bearing with partial slip on the stationary surface. The Reynolds boundary conditions are used in the analysis of journal bearing to predict the extent of the full film region. In the cases of partial slip slider and journal bearing, the pressure distribution is higher compared with the conventional bearing with no slip. In the case of partial slip on both slider and journal bearing surfaces, the single-groove, immediately followed by the partial slip region, results in the increase in pressure distribution. The results also show that in comparison to the conventional bearing with no slip, in the cases of partial slip slider and journal bearing, the shear stress increases before the region of slip/no slip interface, while the shear stress decreases in the region of no slip. In the case of the partial slip region on bearing surfaces, the shear stress distribution is lower in the region immediately after the groove. Significant pressure distribution is obtained due to the influence of partial slip on the slider bearing with uniform film thickness and the concentric journal bearing. The maximum pressure occurs at the end of the region of groove, immediately followed by the region of the partial slip. It is found that the pressure distribution of the slider and journal bearing with partial slip surface are not influenced with the further increase in the nondimensional slip coefficient (A) from 10 to 100.

The Effect of Elastic Distortions on Journal Bearing Performance

1967 ◽  
Vol 89 (4) ◽  
pp. 409-415 ◽  
Author(s):  
J. O’Donoghue ◽  
D. K. Brighton ◽  
C. J. K. Hooke
Keyword(s):  
Exact Solution ◽  
Pressure Distribution ◽  
Elastic Deformation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Wide Range ◽  
Constant Viscosity ◽  
Outside Diameter

This paper presents a solution to the problem of hydrodynamic lubrication of journal bearings taking into account the elastic distortions of the shaft and the bearing. The exact solution for determining the elastic deformation for a given pressure distribution around a bearing is given, together with the reiterative procedure adopted to find the pressure distribution which satisfies both the hydrodynamic and elastic requirements of the system. Results are given which have been derived for a material with a Poisson’s ratio of 0.28, but other values such as 0.33 do not incur substantial errors. The results can be applied to a wide range of operating conditions using the nondimensional group of terms suggested in the paper. The bearing is assumed to be infinite in length, and infinite in thickness. The latter assumption is shown to be valid for a particular case where the outside diameter of the bearing shell is 3.5 times the shaft diameter. A further assumption in the calculation is a condition of constant viscosity of the lubricant existing around the bearing.

The Seal System in Aerostatic Journal Bearings for High Vacuum Chambers

2004 ◽  
Vol 126 (2) ◽  
pp. 310-315 ◽  
Author(s):  
S. Yoshimoto ◽  
Y. Yoshida ◽  
K. Yagi
Keyword(s):  
Pressure Distribution ◽  
Vacuum Chamber ◽  
Journal Bearing ◽  
High Vacuum ◽  
Journal Bearings ◽  
Vacuum Pump ◽  
Chamber Pressure ◽  
Design Parameters ◽  
Vacuum Chambers ◽  
High Vacuum Chamber

This paper investigates the performance of a seal system for an aerostatic journal bearing used in a high vacuum chamber. The seal system consists of axially spaced viscous seals and annular exhaust grooves that are located between the viscous seals. Each exhaust groove is coupled to a separate vacuum pump in order to achieve a vacuum chamber pressure of less than 10−3 Pa. The vacuum chamber pressure is affected by design parameters such as the number of viscous seal stages, seal length, seal gap, and exhaust tube conductance. The influence of these design parameters on the pressure distribution across seal regions and the vacuum chamber pressure are discussed theoretically. It is subsequently shown that an aerostatic journal bearing with three-stage seal system installed can obtain a reduction in the vacuum chamber pressure almost to the ultimate pressure of a vacuum pump, providing there is no leak or outgassing from materials.

A simplified thermohydrodynamic stability analysis of journal bearings

2005 ◽  
Vol 219 (3) ◽  
pp. 225-234 ◽  
Author(s):  
S Singhal ◽  
M. M. Khonsari
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Lubricating Oil ◽  
Damping Coefficients ◽  
Dynamic Coefficients ◽  
Stiffness Coefficients ◽  
Design Charts ◽  
Operating Region ◽  
Rapid Prediction ◽  
The Stability

This work investigates the stability of a journal bearing system, including the effects of inlet viscosity. Simplified thermohydrodynamic design charts for the rapid prediction of stiffness coefficients, damping coefficients, and threshold speed have been developed. This investigation reveals that the inlet viscosity has a pronounced influence on the bearing dynamic coefficients of the lubricating oil film. This investigation also reveals that it is possible to stabilize a journal bearing either by heating the oil or by cooling the oil depending on the operating region.

Experimental study of hydrodynamic pressure distribution in oil lubricated two-axial groove journal bearing

2015 ◽  
Vol 2 (4-5) ◽  
pp. 3453-3462 ◽  
Author(s):  
K.G. Binu ◽  
K. Yathish ◽  
R. Mallya ◽  
B.S. Shenoy ◽  
D.S. Rao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Hydrodynamic Pressure

The Effect of Wavy Groove Liner on Pressure Distribution of Journal Bearing

2013 ◽  
Vol 315 ◽  
pp. 889-893
Author(s):  
Asral Asral ◽  
Jamaluddin Md Sheriff ◽  
Kahar Osman
Keyword(s):  
Pressure Distribution ◽  
Journal Bearing ◽  
Numerical Data ◽  
Fluid Film ◽  
Maximum Pressure ◽  
Cfd Analysis ◽  
Surface Waviness ◽  
Fluid Film Thickness ◽  
Film Lubrication ◽  
Fluid Film Lubrication

The ability of bearing liner to maintain the fluid film lubrication is crucial to its performance. This study is to investigate the pressure distribution for full film lubrication of wavy bearing liner. The results were compared to that from smooth bearing liner. These bearings were used with the palm oil based lubricant. CFD analysis was developed to determine the numerical data. A 60 mm bearing with ratio 0.5 of its diameter to length is simulated. This bearing has 250 µm in clearance and 200 µm in amplitude with semi rectangular circumferential surface waviness liner in shape. Pressure distribution of the bearing was influenced by the increment of the eccentricity ratio and the speed of shaft. The surface waviness liner bearing produces higher in pressure by comparing it with the smooth bearing. The maximum pressure was noted in the vicinity of minimum fluid film thickness where it was distributed at the area around the peak of wave.

scholarly journals Reproducibility of Gaseous Phase Area on Journal Bearing Utilizing Multi-Phase Flow CFD Analysis under Flooded and Starved Lubrication Conditions

Lubricants ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 74 ◽  
Author(s):  
Masayuki Ochiai ◽  
Fuma Sakai ◽  
Hiromu Hashimoto
Keyword(s):  
Surface Tension ◽  
Vapor Pressure ◽  
Gaseous Phase ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Phase Flow ◽  
Cfd Analysis ◽  
Two Phase ◽  
Starved Lubrication ◽  
Lubrication Conditions

It is important to predict the gaseous phase area of journal bearing. However, a detailed calculation method for such gaseous phase areas has not yet been proposed. In this study, the gaseous-phase areas in small bore journal bearings under flooded and starved lubrication conditions are analyzed in terms of the computational fluid dynamics (CFD) of two-phase flow while using a volume of fluid (VOF) method. Furthermore, the influence of surface tension and vapor pressure conditions were investigated, and the analytical and experimental results were compared. The analytical results of VOF for vapor pressure and surface tension were observed to be consistent with the experimental observations under both flooded and starved lubrication conditions. Furthermore, under starved lubrication condition, the analytical results agree well with the observed results for the interface of the oil film and cavitation upon the rupture of the oil film. While using these results, CFD analysis of the two-phase flow of the VOF can be conducted in terms of vapor pressure and surface tension to estimate the gaseous-phase areas of journal bearings under flooded and starved lubrication conditions.

scholarly journals The effect of textured surfaces on the hydrodynamic pressure generation in journal bearings

2018 ◽  
Vol 204 ◽  
pp. 04006
Author(s):  
Muchammad ◽  
Mohammad Tauviqirrahman ◽  
Rizqy Amanullah Akbar ◽  
Fuad Hilmy ◽  
Jamari
Keyword(s):  
Journal Bearing ◽  
Fluid Dynamic ◽  
Surface Texturing ◽  
Hydrodynamic Pressure ◽  
Journal Bearings ◽  
Hydrodynamic Performance ◽  
Textured Surfaces ◽  
Eccentricity Ratio ◽  
Lubrication Performance ◽  
Effect Of Surface

Surface texturing of the lubricated bearing has proven to improve the hydrodynamic performance. The present paper analyzed the effect of surface texturing on the covergent journal bearing with computational fluid dynamic (CFD) approach. The eccentricity ratio, the ratio of textured depth and surface area are the main parameter research. It was shown that for the eccentricity ratio of 0.2, the surface texturing improves the hydrodynamic performance lubrication by increasing the load support. On the otherwise, for the eccentricity ratio of 0.8, the surface texturing does not improve the lubrication performance, even under certain condition, it decreases the lubrication performance of journal bearing.

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