On the behavior of a ferrofluid-lubricated herringbone-grooved hybrid slot-entry bearing

2021 ◽  
pp. 135065012199724
Author(s):  
Satish C Sharma ◽  
Krishnkant Sahu
Keyword(s):  
Finite Element Method ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Continuum Theory ◽  
Iteration Scheme ◽  
Lubricant Film Thickness ◽  
Stability Threshold ◽  
Matlab Code ◽  
Film Stiffness ◽  
Bearing System

The behavior of a slot-entry hybrid herringbone-grooved journal-bearing system lubricated with a ferrofluid lubricant has been numerically studied. The modified Reynolds equation of a ferrofluid bearing model based on the Stokes micro-continuum theory has been numerically solved by a finite-element method. A MATLAB code based on the Gauss–Seidel iteration scheme has been solved to numerically simulate the bearing performance. The simulated results reveal that the use of a ferrofluid lubricant provides enhanced values of lubricant film thickness, fluid film stiffness/damping coefficient, and better stability threshold speed.

Influence of couple stress lubricant on the performance of textured two-lobe slot-entry hybrid journal bearing system

2016 ◽  
Vol 231 (3) ◽  
pp. 366-384 ◽  
Author(s):  
Chandra B Khatri ◽  
Satish C Sharma
Keyword(s):  
Couple Stress ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Critical Mass ◽  
Continuum Theory ◽  
Textured Surface ◽  
Stiffness Coefficients ◽  
Modified Reynolds Equation ◽  
Film Stiffness ◽  
Bearing System

This paper concerns with theoretical investigation to predict the combined influence of textured surface and couple stress lubricant behavior on the performance of circular/two-lobe slot-entry hybrid journal bearing. The flow of incompressible couple stress lubricant through the clearance of a textured journal bearing system is governed by the modified Reynolds equation. The modified Reynolds equation has been derived on the basis of Stokes micro-continuum theory and is solved using a finite element method technique for computing the bearing performance characteristics parameters. The static and dynamic characteristics of circular/two-lobe slot-entry hybrid journal bearing have been computed for textured and non-textured bearings with influence of couple stress lubricant. The present study indicates that the influence of couple stress lubricant behavior is significantly more on the values of fluid film stiffness coefficients [Formula: see text], critical mass of journal [Formula: see text], and stability threshold speed margin [Formula: see text] for textured surface than that of non-textured surface in case of a slot-entry hybrid journal bearing system.

scholarly journals A Comparative Elastohydrostatic Analysis of CFV- and Capillary-Compensated Multirecess Hydrostatic/Hybrid Journal Bearing Operating with Micropolar Lubricant

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Suresh Verma ◽  
Vijay Kumar ◽  
K. D. Gupta
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Comparative Study ◽  
Elastic Deformation ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Constant Flow ◽  
Bearing System ◽  
Flow Valve

A comparative study on the performance characteristics of the flexible multirecess hydrostatic journal bearing system with constant flow valve and capillary restrictors has been presented considering the effect of micropolar parameters. The modified Reynolds equation for the flow of micropolar lubricant through the bearing has been solved using finite element method, and the resulting elastic deformation in the bearing shell has been determined iteratively. The results indicate that the micropolar parameters of the lubricant affect the performance of the flexible multirecess hydrostatic journal bearing system quite significantly.

Theoretical investigation of surface texture effects on the performance characteristics of hydrodynamic two-lobe journal bearing

2020 ◽  
Vol 234 (11) ◽  
pp. 1712-1725
Author(s):  
Niranjan Singh ◽  
RK Awasthi
Keyword(s):  
Finite Element Method ◽  
Theoretical Investigation ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Surface Texturing ◽  
Performance Characteristics ◽  
Performance Parameters ◽  
Eccentricity Ratio ◽  
Static Performance ◽  
Bearing System

In the present work, theoretical investigation has been performed to predict the influence of spherical textures on the performance characteristics of two-lobe journal bearing system. The flow of lubricant in the clearance space between the bearing and the journal is governed by the Reynolds equation assuming the flow is Newtonian and isoviscous. The Reynolds equation is solved using a finite element method and the static performance parameters of circular/two-lobe smooth/textured journal bearing system have been computed with variation in eccentricity ratio, dimple depth and its location. The numerically simulated results reveal that the partial surface texturing can provide better performance when the textures are created in the pressure build-up region of 126°–286° and the dimple aspect ratio is nearly 1.0.

A Study of Misaligned Micropolar Lubricated Membrane Compensated Hybrid Journal Bearing System

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Satish C. Sharma ◽  
E. Rajasekhar Nicodemus ◽  
Nathi Ram
Keyword(s):  
Reynolds Equation ◽  
Flow Characteristic ◽  
Journal Bearing ◽  
Lubricating Oil ◽  
Micropolar Theory ◽  
Shaft Deflection ◽  
Journal Misalignment ◽  
Raphson Method ◽  
System Operating ◽  
Bearing System

The present work aims to analytically study the performance of misaligned four-pocket, membrane compensated, hybrid journal bearing system operating with micropolar lubricant. In the present study, the flow characteristic of the lubricating oil containing additives and contaminants has been modeled using Erigen’s micropolar theory. The journal misalignment which may occur as a result of noncentral loading, improper assembly, shaft deflection due to elasticity and thermal distortions, etc. has been accounted for in the present study by defining a pair of misalignment parameters in vertical and horizontal directions (i.e., δ and σ).The modified Reynolds equation governing the flow of micropolar lubricant in the clearance space of a misaligned bearing has been solved using FEM and Newton Raphson method along with the appropriate boundary conditions. The numerically simulated results suggest that the effect of journal misalignment is to cause degradation in bearing performance, whereas the influence of micropolar effect of lubricant is to enhance the bearing performance. Therefore, it is imperative to account for the effect of misalignment and lubricant behavior during the design process in order to generate accurate bearing characteristics data.

Effect of CSL on the characteristics of six-pocket hybrid irregular journal bearing

2020 ◽  
pp. 135065012093685
Author(s):  
Abhishake Chaudhary ◽  
Arvind K Rajput ◽  
Rajiv Verma
Keyword(s):  
Couple Stress ◽  
Reynolds Equation ◽  
Pressure Field ◽  
Journal Bearing ◽  
Characteristic Parameters ◽  
Galerkin’S Method ◽  
Bearing Clearance ◽  
Bell Mouth ◽  
Bearing Characteristic ◽  
Bearing System

This article examines the effect of couple stress lubricant on the characteristics of six-pocket hybrid irregular journal bearing system. Various shapes of irregular journals viz. barrel, bell-mouth, and undulated journal are considered in the analysis. To model the behavior of the flow of couple stress lubricant in bearing clearance space, the modified form of Reynolds equation is derived by using Stokes theory. The unknown pressure field in Reynolds equation is determined by using Galerkin's method. To illustrate the effect of couple stress lubricant on bearing system, the results for characteristics parameters of journal bearing system are presented. The results noticeably reveal that the presence of different geometrical irregularities in journal may ominously influence the performance of bearing system. Further, the use of couple stress lubricant instead of Newtonian lubricant offers a significant improvement in the value of bearing characteristic parameters of geometrically irregular hybrid journal bearing system viz. [Formula: see text], [Formula: see text] and [Formula: see text].

Behaviour of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and micropolar lubricant

2017 ◽  
Vol 69 (6) ◽  
pp. 844-862 ◽  
Author(s):  
Chandra B. Khatri ◽  
Satish C. Sharma
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Technique ◽  
Surface Texturing ◽  
Textured Surface ◽  
Performance Parameters ◽  
Content Type ◽  
Fluid Theory ◽  
Bearing System

Purpose The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal bearing system. The bearing performance parameters of the textured circular/two-lobe hole-entry hybrid journal bearing system have been computed against the constant vertical external load supported by the bearing. Design/methodology/approach In this work, Eringen’s micropolar fluid theory has been used to derive the governing Reynolds equation. The consequent solution of the governing Reynolds equation has been obtained by using finite element method (FEM) numerical technique. Findings The present study indicates that the use of the textured surface, two-lobe profile of bearing and micropolar lubricant, significantly enhances the bearing performance as compared to non-textured circular journal bearing. Originality/value The present study concerning the influence of surface texturing on the behaviour of the two-lobe hole-entry hybrid journal bearing lubricated with micropolar lubricant is original. The theoretically simulated results of the present study will be useful to design an efficient journal bearing system.

scholarly journals Performance of an Orifice Compensated Two-Lobe Hole-Entry Hybrid Journal Bearing

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
J. Sharana Basavaraja ◽  
Satish C. Sharma ◽  
S. C. Jain
Keyword(s):  
External Load ◽  
Design Parameter ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Damping Coefficients ◽  
Symmetric Configuration ◽  
Flow Through ◽  
Direct Stiffness ◽  
Offset Factor ◽  
Bearing System

The work presented in this paper aims to study the performance of a two-lobe hole-entry hybrid journal bearing system compensated by orifice restrictors. The Reynolds equation governing the flow of lubricant in the clearance space between the journal and bearing together with the equation of flow through an orifice restrictor has been solved using FEM and Galerkin's method. The bearing performance characteristics results have been simulated for an orifice compensated nonrecessed two-lobe hole-entry hybrid journal bearing symmetric configuration for the various values of offset factor , restrictor design parameter , and the value of external load . Further, a comparative study of the performance of a two-lobe hole-entry hybrid journal bearing system with a circular hole-entry symmetric hybrid journal bearing system has also been carried out so that a designer has a better flexibility in choosing a suitable bearing configuration. The simulated numerical results indicate that for the two-lobe symmetric hole-entry hybrid journal bearing system with an offset factor greater than one provides 30 to 50 percent larger values of direct stiffness and direct damping coefficients as compared to a circular symmetric hole-entry hybrid journal bearing system.

The Influence of Orifice Restriction on the Stability of Rigid Rotor-Aerostatic Bearing System

2009 ◽  
Author(s):  
Cheng-Hsien Chen ◽  
Ding-Wen Yang ◽  
Yuan Kang ◽  
Ren-Ming Hwang ◽  
Shrh-Shyong Shyr
Keyword(s):  
Reynolds Equation ◽  
Inertial Force ◽  
Adiabatic Process ◽  
Rigid Rotor ◽  
Double Row ◽  
Stability Threshold ◽  
Spindle Rotation ◽  
The Stability ◽  
Air Film ◽  
Bearing System

This paper has studied the influence of the restriction effect on the stability of a rigid rotor in rotation supported by double-row, orifice compensated aerostatic bearings. The air which is assumed to be perfect gas, passes through orifice restrictor into the bearing clearance undergoing the adiabatic process is governed by Reynolds equation including the coupled effects of wedge due to spindle rotation and squeezed film due to journal oscillation. The Ph-method is used to analyze Reynolds equation and which is then solved by the finite difference method and numerical integration to yield static and dynamic characteristics of air film. The motion equation of the rotor-bearing system is obtained by using the perturbation method and the eigensolution method is used to determine the stability threshold and critical whirl ratio. The variations of stability threshold of both critical inertial force and critical whirl ratio with restriction parameters are analyzed for various whirl ratios, speed of journal rotation and eccentricity ratios.

Static and Dynamic Analysis of Capillary Compensated Hydrostatic Journal Bearings by Finite Element Method

1977 ◽  
Vol 99 (4) ◽  
pp. 478-484 ◽  
Author(s):  
D. V. Singh ◽  
R. Sinhasan ◽  
R. C. Ghai
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Journal Bearing ◽  
Dynamic Performance ◽  
Critical Mass ◽  
Equations Of Motion ◽  
Stability Studies ◽  
Static And Dynamic Analysis ◽  
Bearing System ◽  
Element Method

Using finite element method steady state and dynamic performance of a capillary compensated hydrostatic journal bearing have been investigated. For stability studies, the critical mass of the bearing system has been determined by Routh’s criterion. The locus of the journal center has been predicted by discretizing time and numerically integrating the equations of motion governing the journal bearing system.

Performance of Externally Pressurized Dry Gas Seal

2011 ◽  
Vol 335-336 ◽  
pp. 610-614 ◽  
Author(s):  
Wei Bing Zhu ◽  
Sheng Ren Zhou ◽  
He Shun Wang
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Reynolds Equation ◽  
Dry Gas Seal ◽  
Supply Pressure ◽  
Lubrication Equation ◽  
Air Supply ◽  
Computer Numerical Simulation ◽  
Film Stiffness

By adding the flow rate of throttle orifice to conventional stable externally pressurized gas lubrication equation, the Reynolds equation for externally pressurized dry gas seal with orifice compensation is established. The solution of the equation is studied by functional extremum algorithm and finite element method, and the computer numerical simulation is carried out in Matlab software. The effects of air supply pressure, numbers and diameter of throttle orifice, on face opening force and gas film stiffness are discussed in detail.

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