Magneto-Hydrodynamics of Lubricant in Recessed Conical Hybrid Journal Bearing with Taper Error

2020 ◽  
pp. 1-24
Author(s):  
Abhishek Kumar ◽  
Satish Chandra Sharma
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Width Ratio ◽  
Element Analysis ◽  
Surface Error ◽  
Performance Accuracy ◽  
Minimum Residual ◽  
The Impact ◽  
Raphson Method

Abstract To improve the performance accuracy of a conical journal bearing system, the surface error needs to be considered in the analysis since a tiny difference in dimensional values can alter the performance; the consideration of surface error may degrade the performance behaviour of bearing. However, a better way to overcome such degradation may be to make use of magneto-hydrodynamics of fluid. Therefore, the present work is planned to investigate the impact of taper error and magneto-hydrodynamic (MHD) lubricant in recessed conical hybrid journal bearing. In present paper, the Reynolds equation is derived under stated assumptions along with frictional power loss expression and finally solved using Finite Element Analysis, Newton-Raphson method and Generalized Minimum RESidual method. The conducted research helped in determination of optimum values of recess width, land-width ratio and restrictor design parameter; and also obtaining the results corresponding to distinct performance indices. The outcome of these results may inspire practising designers for development of better tribo-components.

scholarly journals An Analytical Method for the Determination of Temperature Distribution in Short Journal Bearing Oil Film

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 539
Author(s):  
Nebojsa Nikolic ◽  
Zivota Antonic ◽  
Jovan Doric ◽  
Dragan Ruzic ◽  
Stjepan Galambos ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Oil Film ◽  
Symmetric Geometry ◽  
Experimental Values ◽  
Operating Regimes ◽  
Level Of Agreement

The aim of this paper is to derive an equation for the temperature distribution in journal bearing oil film, in order to predict the thermal load of a bearing. This is very important for the prevention of critical regimes in a bearing operation. To achieve the goal, a partial differential equation of the temperature field was first derived, starting from the energy equation coupled with the Reynolds equation of hydrodynamic lubrication for a short bearing of symmetric geometry. Then, by solving the equation analytically, the function of temperature distribution in the bearing oil film has been obtained. The solution is applied to the journal bearing, for which the experimental data are available in the references. Finally, the obtained results have been compared to the corresponding experimental values for two operating regimes, and a good level of agreement was achieved.

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.

Theoretical Analysis of Externally Pressurized Air Journal Bearing

1970 ◽  
Vol 12 (2) ◽  
pp. 123-129 ◽  
Author(s):  
B. C. Majumdar
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Design Parameters ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Dimensional Parameters ◽  
Bearing Design

A theoretical investigation is made to predict the performance of an externally pressurized air journal bearing having several pressure sources. The pressure distribution, which leads to the determination of load-carrying capacity and flow requirement, is obtained by solving Reynolds equation numerically. The load and flow, expressed in non-dimensional parameters, are presented for different bearing design parameters (dimensionless). The results predicted by this method are compared with others' experimental data.

scholarly journals EVALUATION OF S.I.F FOR CRACK EMANATING AT 450 ORIENTATION FROM A HOLE IN PRESSURISED CYLINDER USING FEA

2013 ◽  
pp. 264-268
Author(s):  
AKASH.D. A ◽  
ANAND. A ◽  
G.V.GNANENDRA REDDY ◽  
SUDEV.L. J
Keyword(s):  
Fracture Mechanics ◽  
Physical Structure ◽  
External Boundary ◽  
Material Interfaces ◽  
Element Analysis ◽  
Vessel Structure ◽  
Machine Elements ◽  
Displacement Extrapolation Method ◽  
The Impact

The use of fracture mechanics techniques combining with Finite Element Analysis [F.E.A] in assessment of performance and reliability of pressure vessel structure is on demand .The machine elements with cylindrical profile such as cylindrical shells, which are used extensively as the structural configuration in aerospace and shipping industries needs to be leak proof. But during their service life, a crack may initiate on internal/external boundary of circular cylinder which influences on stress distribution in the structure. All flaws in a physical structure may not always have the same orientation relative to boundaries and material interfaces. In fracture mechanics, Stress Intensity Factor (SIF) is an important criterion to evaluate the impact of crack as the magnitude of SIF determines the propagation of crack. This paper reviews on investigation of S.I.F for 45 deg arbitrarily oriented flaw emanating from a hole in pressurised cylinder using Displacement Extrapolation Method (DEM) in F.E.M that would aid in the determination of the critical nature of such flaws.

Determination of Gasket Stress Levels During Thermal Transients

2002 ◽  
Author(s):  
Warren Brown ◽  
Michel Derenne ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Thermal Loading ◽  
Temperature Response ◽  
Fluid Temperature ◽  
Research Project ◽  
Element Analysis ◽  
Worst Case ◽  
Thermal Transients ◽  
Stress Levels ◽  
The Impact

The leakage of bolted flange joints at high temperature or during transient thermal shock is a well recognised problem. However, the present pressure vessel design codes do not address the effects of temperature on the integrity of the bolted joint, other than material properties. A research project currently being conducted at Ecole Polytechnique is intended to provide designers with an analytic approach for establishing the effects of thermal loading on the joint sealing ability. This paper is the fourth to be published as part of this research project. The presented analysis method enables the determination of the temperature response of the joint components to a transition in internal fluid temperature. Using this data, the worst case operating scenario may be selected and calculations performed to determine the impact of the temperature transition on the gasket stress levels. The presented analytical method is verified by comparison to finite element analysis and experimental measurement.

Effect of wear on the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation

2019 ◽  
Vol 233 (9) ◽  
pp. 1277-1292 ◽  
Author(s):  
Sanjay R Pawar ◽  
Vikas M Phalle
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Radial Clearance ◽  
Constant Flow ◽  
Performance Parameters ◽  
Element Analysis ◽  
Spherical Coordinate ◽  
Flow Valve

Hybrid bearings gets worn gradually during the start and stop operation. This wearing leads to change in the geometry of bearing and affects the radical clearance as well as fluid film thickness. Therefore, these discontinuities in the radial clearance can influence the performance characteristics. With the purpose of preventing irreparable failure state of bearing assembly, it is essential to concentrate on the actual changes in the performance parameters of hole entry hybrid conical journal bearing due to wear. In this context, the main aim of this analysis is to predict the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation. Modified Reynolds equation in spherical coordinate form is used to govern the flow of lubricant in the narrow region between journal and conical bearing. The solution to this Reynolds equation is obtained by finite element analysis with appropriate boundary conditions. This paper summarizes that for a given bearing with constant flow valve as compensating element, the wear causes variation in lubricant film thickness, which strongly affects load capacity, pressure generated, and dynamic performance parameters.

Optimal Parameters of Grooved Conical Hybrid Journal Bearing With Shear Thinning and Piezo-viscous Lubricant Behavior

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Abhishek Kumar ◽  
Satish C. Sharma
Keyword(s):  
Axial Load ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Cone Angle ◽  
Shear Thinning ◽  
Optimal Parameters ◽  
Hydrodynamic Modes ◽  
Axial Load Capacity ◽  
Minimum Residual

To harness higher axial load capacity, a larger cone angle is used in conical bearings, resulting in an increase in the surface area which in turn increases the frictional power loss. The use of microgrooves in journal bearing helps in controlling this loss. Therefore, the present work is aimed to analyze conical hybrid journal bearing (i.e., combination of hydrostatic and hydrodynamic modes of operation) consisting of microgrooves along with shear thinning and piezo-viscous behavior of the lubricant. In this study, the microgroove attributes have been optimized by obtaining the solution of a Reynolds equation using finite element method and generalized minimum residual scheme (GMRES). These optimized groove attributes are used for numerically simulating the performance of the conical bearings. It has been observed that the best features of microgrooves and shear thinning behavior of the lubricant can be extracted to achieve better performance of the bearings. The results presented in this study are believed to be beneficial to the bearing designers and practising lubrication engineers.

scholarly journals Optimum Groove Location of Hydrodynamic Journal Bearing Using Genetic Algorithm

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Lintu Roy ◽  
S. K. Kakoty
Keyword(s):  
Genetic Algorithm ◽  
Sequential Quadratic Programming ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Mass Parameter ◽  
Load Flow ◽  
Flow Coefficient ◽  
Optimum Performance ◽  
Hydrodynamic Journal Bearing

This paper presents the various arrangements of grooving location of two-groove oil journal bearing for optimum performance. An attempt has been made to find out the effect of different configurations of two groove oil journal bearing by changing groove locations. Various groove angles that have been considered are 10°, 20°, and 30°. The Reynolds equation is solved numerically in a finite difference grid satisfying the appropriate boundary conditions. Determination of optimum performance is based on maximization of nondimensional load, flow coefficient, and mass parameter and minimization of friction variable using genetic algorithm. The results using genetic algorithm are compared with sequential quadratic programming (SQP). The two grooved bearings in general have grooves placed at diametrically opposite directions. However, the optimum groove locations, arrived at in the present work, are not diametrically opposite.

Ferrofluid Lubrication of Optimized Spiral-Grooved Conical Hybrid Journal Bearing using Current Carrying Wire Model

2021 ◽  
pp. 1-51
Author(s):  
Abhishek Kumar ◽  
Satish Chandra Sharma
Keyword(s):  
Magnetic Field ◽  
Magnetic Field Generation ◽  
Cross Sectional ◽  
Minimum Residual ◽  
Magnetic Field Model ◽  
System 2 ◽  
Optimal Values ◽  
Spiral Grooves ◽  
Raphson Method

Abstract In order to systematically investigate the behaviour of fluid-film bearing, the determination of optimal parameters is of utmost importance. The core contributions of this paper are (1) modeling of the conical bearing for spiral-grooves with ferrofluid lubrication using current carrying wire model for fixed coordinate system, (2) deriving the expressions for magnetic field model and frictional power loss other than Reynolds equation for ferrofluid lubrication, and (3) evaluation of optimal values of spiral-grooved bearing surface for different cross-sectional shapes and that of current carrying wire model for magnetic field generation in ferrofluid lubrication. Generalized Minimum RESidual iterative solver and Newton-Raphson method has facilitated the solution of complex non-linear Finite Element (FE) formulated governing equations. Initially, the results have been obtained for determining the optimal values of spiral-groove and ferrofluid model attributes. After that, using these optimal values, corresponding performance indicators are evaluated. It was found that there exists a optimum value of different geometric features for distinct cross-sectional shapes of spiral-grooves.

Orifice compensated performance characteristics of hybrid hole-entry conical journal bearing

2016 ◽  
Vol 231 (3) ◽  
pp. 316-331 ◽  
Author(s):  
Prashant G Khakse ◽  
Vikas M Phalle ◽  
SS Mantha
Keyword(s):  
Coordinate System ◽  
System Performance ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Spherical Coordinate ◽  
Cylindrical Coordinate ◽  
Newton Raphson ◽  
Fluid Film Thickness ◽  
Raphson Method

Influence of semi-cone angles on the performance of the non-recessed hybrid/hydrostatic hole-entry conical journal bearing compensated with orifice restrictor has been carried out analytically. The analysis comprises two rows of symmetric hole-entry contour in the circumferential direction of hybrid/hydrostatic conical journal bearing. An orifice restrictor is used in the hole-entry contour to allow the restricted flow in the clearance space of a journal and bearing. Well-known finite element method and Newton–Raphson method for restrictor have been used to solve the Reynolds equation, governing the fluid flow in the clearance space of a hybrid/hydrostatic conical journal and bearing. Further, the spherical coordinate system has been employed to solve Reynolds equation instead of cylindrical coordinate system. Performance characteristics in terms of stiffness coefficient, damping coefficient, bearing pressure, bearing flow, and minimum fluid film thickness have been discussed for variable external radial load ([Formula: see text]) = 0.25–1.5. The performance characteristics in terms of [Formula: see text], [Formula: see text], and [Formula: see text] is found to be quite significant for hybrid hole-entry conical journal bearing when compared with hydrostatic hole-entry conical journal bearing, which allows the designer to choose appropriate non-recessed hybrid hole-entry conical journal bearing.

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