Mixed Lubrication of Coupled Journal-Thrust-Bearing Systems Including Mass Conserving Cavitation

2003 ◽  
Vol 125 (4) ◽  
pp. 747-755 ◽  
Author(s):  
Yansong Wang ◽  
Q. Jane Wang ◽  
Chih Lin
Keyword(s):  
Conformal Mapping ◽  
Boundary Conditions ◽  
Thrust Bearing ◽  
Mixed Lubrication ◽  
Mapping Technique ◽  
Computational Domain ◽  
Misalignment Angle ◽  
Governing Equations ◽  
Reynolds Equations ◽  
Bearing System

A mixed lubrication model is developed to investigate the lubrication of coupled journal-thrust-bearing systems. The governing equations are mapped into a computational domain with a conformal mapping technique developed in a previous study by Wang et al. (2002). In order to study the influence of the boundary conditions on the performance of the bearing system, either the Reynolds boundary conditions or the JFO’s mass conserving conditions are applied to the governing Reynolds equations. The performance of a typical coupled journal-thrust bearing system is numerically investigated and the effects of viscosity, misalignment angle and feeding scheme are discussed.

Large Thrust Bearing Modeling: Influence of Thermal Boundary Conditions and Runner Deformations on Results of TEHD Analysis

2011 ◽  
Author(s):  
Michal Wodtke ◽  
Michel Fillon ◽  
Andreas Schubert ◽  
Michal Wasilczuk
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Boundary Conditions ◽  
Thrust Bearing ◽  
Measurement Data ◽  
Water Power ◽  
Thermal Boundary Conditions ◽  
Side Walls ◽  
Theoretical Results ◽  
Bearing System

In the paper, numerical TEHD results for one of the biggest water power plant Itaipu were compared to available measurement data. Numerical simulations were carried out with the use of bearing model for which the accuracy was previously confirmed with the measurements available for smaller bearings. Several cases were analyzed. The only differences between the cases are the applied boundary conditions. The influence of heat transfer coefficient assumed at bearing pad side walls and collar deformation on predicted bearing performance was determined. Some conclusions concerning large thrust bearing modeling were drawn on the basis of comparisons of the theoretical results to measurements for analyzed bearing system.

The Thermally Boosted Oil Lubricated Sliding Thrust Bearing

1974 ◽  
Vol 96 (3) ◽  
pp. 322-328 ◽  
Author(s):  
C. M. Rodkiewicz ◽  
J. C. Hinds ◽  
C. Dayson
Keyword(s):  
Boundary Conditions ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Governing Equations ◽  
Temperature Ratio ◽  
Thrust Bearings ◽  
Temperature Boundary ◽  
Load Carrying

The effect of varying the ratio of slider to pad temperature boundary conditions and the influence of varying inlet to outlet ratio of a plane infinitely wide slider bearing is examined. The lubricant is assumed to be incompressible and the variation of viscosity with temperature is taken into account. The nondimensionalized governing equations, transformed in terms of the stream function, are solved numerically. The results show that maintaining a lower slider temperature to pad temperature ratio causes an increase in the load carrying capacity of the bearing. A means of which advantage could be taken of this effect in the design of thrust bearings is suggested.

Core Variation in an Externally Pressurized Converging Thrust Bearing with Bingham Lubricant

2016 ◽  
Vol 852 ◽  
pp. 428-434 ◽  
Author(s):  
I. Jayakaran Amalraj ◽  
G. Alexander Raymand
Keyword(s):  
Film Thickness ◽  
Boundary Conditions ◽  
Yield Surface ◽  
Constitutive Equations ◽  
Thrust Bearing ◽  
Numerical Solutions ◽  
Flow Region ◽  
Core Region ◽  
Governing Equations ◽  
The Core

The effects of angle of convergence on the shape and thickness of the core are analyzed theoretically by considering variable film thickness in an externally pressurized circular thrust bearing. Using the assumptions of the lubrication theory, modified Reynold’s equation and the governing equations are obtained. Using the boundary conditions of the problem in the constitutive equations we get the velocity of the core region as well as flow region. By considering the equilibrium of an element in the yield surface, an algebraic equation to determine the thickness of the yield surface is derived. Numerical solutions are obtained for the thickness of yield surface and velocities for various values of Bingham Numbers and the angle of convergence.

scholarly journals Vibration of rotating circular cylindrical shells with distributed springs

2021 ◽  
Vol 37 ◽  
pp. 346-358
Author(s):  
Fuchun Yang ◽  
Xiaofeng Jiang ◽  
Fuxin Du
Keyword(s):  
Boundary Conditions ◽  
Galerkin Method ◽  
Shell Theory ◽  
Rotation Speed ◽  
Cylindrical Shells ◽  
Free Vibrations ◽  
Governing Equations ◽  
Natural Response ◽  
Circular Cylindrical Shells ◽  
The Galerkin Method

Abstract Free vibrations of rotating cylindrical shells with distributed springs were studied. Based on the Flügge shell theory, the governing equations of rotating cylindrical shells with distributed springs were derived under typical boundary conditions. Multicomponent modal functions were used to satisfy the distributed springs around the circumference. The natural responses were analyzed using the Galerkin method. The effects of parameters, rotation speed, stiffness, and ratios of thickness/radius and length/radius, on natural response were also examined.

Structure of the Flow Associated with a Two-Dimensional Supersonic Intake

1965 ◽  
Vol 16 (2) ◽  
pp. 122-138 ◽  
Author(s):  
L. F. Henderson
Keyword(s):  
Boundary Conditions ◽  
Flow Structure ◽  
Analytical Procedure ◽  
Qualitative Description ◽  
Mapping Technique ◽  
Two Dimensional ◽  
Shock System

SummaryThe intake is conceived as a device that generates a shock system and a subsonic patch within a supersonic field. The object of the paper is to obtain a qualitative description of this flow structure. The analytical procedure is a simple but fairly powerful mapping technique. Several examples are discussed and these show how the flow on the intake alters under the influence of gradually changing boundary conditions.

Numerical Analysis of a Coupled Porous Journal and Thrust Bearing System

2005 ◽  
Vol 127 (1) ◽  
pp. 120-129 ◽  
Author(s):  
Takuji Kobayashi ◽  
Hiroshi Yabe
Keyword(s):  
Thrust Bearing ◽  
Dynamic Performance ◽  
Internal Flow ◽  
Disk Drive ◽  
Rotating Shaft ◽  
Static And Dynamic Characteristics ◽  
Bottom Face ◽  
Magnetic Hard Disk ◽  
Bearing System ◽  
Porous Sleeve

A numerical model has been developed to analyze both static and dynamic characteristics of a coupled porous journal and thrust bearing system that is used to support a rotating shaft in a magnetic hard disk drive. The analyzed system is composed of a porous sleeve, a herringbone-grooved solid thrust plate and a flanged shaft, where the bottom end is closed to form a cantilever spindle. The inner surface and the bottom face of the porous sleeve operate as a herringbone-grooved journal and thrust bearing, respectively. The model is based on the narrow groove theory for the bearing oil film, and Darcy’s law for the internal flow in the porous sleeve. The pressure distribution, static equilibrium position of the shaft and dynamic coefficients are obtained under a given external axial load. There exists a window of permeability of the porous sleeve that presents significant advantage to prevent the creation of a sub-ambient condition and to maintain a large thrust bearing film thickness at the expense of some loss of dynamic performance.

Application of Generalized Differential Quadrature Method to the Bending of Thick Laminated Plates with Various Boundary Conditions

2006 ◽  
Vol 5-6 ◽  
pp. 407-414 ◽  
Author(s):  
Mohammad Mohammadi Aghdam ◽  
M.R.N. Farahani ◽  
M. Dashty ◽  
S.M. Rezaei Niya
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Simple Procedure ◽  
Shear Deformation Theory ◽  
Laminated Plates ◽  
Differential Quadrature ◽  
Governing Equations ◽  
First Order ◽  
Various Boundary Conditions ◽  
Generalized Differential

Bending analysis of thick laminated rectangular plates with various boundary conditions is presented using Generalized Differential Quadrature (GDQ) method. Based on the Reissner first order shear deformation theory, the governing equations include a system of eight first order partial differential equations in terms of unknown displacements, forces and moments. Presence of all plate variables in the governing equations provide a simple procedure to satisfy different boundary condition during application of GDQ method to obtain accurate results with relatively small number of grid points even for plates with free edges .Illustrative examples including various combinations of clamped, simply supported and free boundary condition are given to demonstrate the accuracy and convergence of the presented GDQ technique. Results are compared with other analytical and finite element predictions and show reasonably good agreement.

Numerical Investigation of a Fiber Web Effect on the Pressure Drop and Particles Collection in a Microchannel

2009 ◽  
Author(s):  
Alireza Dastan ◽  
Omid Abouali
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Numerical Investigation ◽  
Particle Motion ◽  
Particle Deposition ◽  
Hydraulic Diameter ◽  
Lagrangian Approach ◽  
Computational Domain ◽  
Governing Equations ◽  
Eulerian Approach

In this paper pressure drop and particle deposition in a microchannel with a hydraulic diameter of 225 micrometer is investigated numerically. Several hundred micron length fibers caught at the entrance of the channels making a “fiber web” also is modeled in this research. Governing equations for the flow field are solved with an Eulerian approach while the equations of particle motion in the flow are solved by a Lagrangian approach. Assuming the symmetry in the domain, one channel and the corresponding plenum are studied in the computational domain. For studying the effects of fibers in the flow, two fiber webs with four and six solid fibers are studied. The increase of pressure drop in the microchannel because of the entrance fiber web is computed and discussed. Also deposition and collection of the particles with various diameters at the fiber webs are also presented.

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