Thermoelastohydrodynamic (TEHD) Analysis of a Grooved Thrust Washer

2004 ◽  
Vol 126 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Bogdan R. Kucinschi ◽  
Kenneth J. DeWitt ◽  
Mircea D. Pascovici
Keyword(s):  
Reynolds Equation ◽  
Energy Equation ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Thermally Induced ◽  
Thermal Deformations ◽  
Solid Media ◽  
Elasticity Equations ◽  
Flow Phenomena ◽  
Raphson Iteration

A numerical model is developed to analyze the influence of thermal deformations on the performance of a radially grooved thrust washer. The analysis couples the flow phenomena (including cavitation) in the lubricant with the heat transfer in both the fluid and solid media, as well as with the thermally induced deformations in the solid parts. The finite element method (both two-dimensional and three-dimensional, with linear and quadratic shape functions) is used to solve the Reynolds equation for flow, the energy equation for temperature and the thermo-elasticity equations for deformations in the solid. Grid coupling is achieved by using a Newton-Raphson iteration. Realistic boundary conditions and geometry are used for the fluid and solid domains. The results show that, for the case of a properly shaped stator, the thermal deformations can lead to an increase in bearing performance.

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.

An Analysis of Grease and Oil Lubricated Spiral Grooved Bearings

1974 ◽  
Vol 96 (2) ◽  
pp. 275-283
Author(s):  
D. M. Dewar
Keyword(s):  
Reynolds Equation ◽  
Energy Equation ◽  
Three Dimensional ◽  
Thermal Conditions ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Through Flow ◽  
Load Carrying ◽  
Running Torque ◽  
Spiral Groove Bearing

Mathematical models for grease and oils are put forward and used to solve a two-dimensional Reynolds’ equation with a quasi three-dimensional energy equation for any geometry of spiral groove bearing. Using numerical methods, results are presented for the temperature distributions in through-flow and block-centered thrust bearings; conical bearings and herringbone grooved journal bearings can also be dealt with. The overall bearing parameters, namely, load-carrying capacity, stiffness, and running torque at various eccentricity ratios are shown along with their dependence upon the prevailing thermal conditions.

A Study of Thermohydrodynamic Features of Multi Wound Foil Bearing Using Lobatto Point Quadrature

2008 ◽  
Author(s):  
Kai Feng ◽  
Shigehiko Kaneko
Keyword(s):  
High Speed ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Three Dimensional ◽  
Iteration Process ◽  
Element Model ◽  
Air Bearings ◽  
Foil Bearing ◽  
Deformation Equation ◽  
Wide Range

The applications of foil air bearings, which are recognized to be the best choice for oil free applications, have been extended for use in a wide range of turbo-miachineries with high speed and high temperature. Lubricant temperature becomes an important factor in the performance of foil air bearings, especially at high rotational speeds and high loads or at high ambient temperature. However, most of the published foil air bearing models were based on the isothermal assumption. This study presents a thermohydrodynamic analysis (THD) of Multi Wound Foil Bearing (MWFB), in which the Reynolds’ equation is solved with the gas viscosity as a function of temperature that is obtained from the energy equation. Lobatto point quadrature, which was proposed by Elrod and Brewe and introduced into compressible calculation by Moraru and Keith, is utilized to accelerate the iteration process with a sparse mesh across film thickness. A finite element model of the foil is used to describe the foil elasticity. An iterative procedure is performed between the Reynolds’ equation, the foil elastic deformation equation and the energy equation, until the convergence is achieved. A three-dimensional temperature prediction of air film is presented and a comparison of THD to isothermal results is made to emphasize the importance of thermal effects. Finally, published experimental data are used to validate this numerical solution.

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.

Thermohydrodynamic Study of Multiwound Foil Bearing Using Lobatto Point Quadrature

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Kai Feng ◽  
Shigehiko Kaneko
Keyword(s):  
High Speed ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Three Dimensional ◽  
Iteration Process ◽  
Element Model ◽  
Air Bearings ◽  
Foil Bearing ◽  
Wide Range ◽  
Air Film

The applications of foil air bearings have been extended for use in a wide range of turbomachineries with high speed and high temperature. Lubricant temperature becomes an important factor in the performance of foil air bearings, especially at high rotational speeds and high loads or at high ambient temperature. This study presents a thermohydrodynamic (THD) analysis of multiwound foil bearing, in which the Reynolds’ equation is solved with gas viscosity as a function of temperature that is obtained from the energy equation. Lobatto point quadrature is utilized to accelerate the iteration process with a sparse mesh across film thickness. A finite element model of the foil is used to describe the foil elasticity. An iterative procedure is performed between the Reynolds equation, the foil elastic deflection equation, and the energy equation until convergence is achieved. A three-dimensional temperature prediction of air film is presented, and a comparison of THD to isothermal results is made to emphasize the importance of thermal effects. Finally, published experimental data are used to validate this numerical solution.

Solution of the Elastohydrodynamic Finite Journal Bearing Problem

1973 ◽  
Vol 95 (3) ◽  
pp. 342-351 ◽  
Author(s):  
K. P. Oh ◽  
K. H. Huebner
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Solution Procedure ◽  
Iteration Scheme ◽  
Bearing Material ◽  
Constant Property ◽  
Elasticity Equations ◽  
Minimum Film Thickness ◽  
Three Dimensional Elasticity

Finite-element techniques are applied to solve the elastohydrodynamic finite journal bearing problem. Reynolds’ equation for the fluid film and the three-dimensional elasticity equations for the bearing housing are solved simultaneously using a unique iteration scheme. The analysis yields the pressure distribution and the displacement distribution which satisfy the elastohydrodynamic requirements of realistic three-dimensional bearing geometries. From these distributions, important information such as the stresses in the bearing material and the minimum film thickness in the lubricant can be calculated. In the calculations it is assumed that the bearing operates with a constant-property lubricant and a linearly elastic bearing material. The solution procedure is applied to a typical problem and numerical results are presented.

Oil-Film Temperature Distribution in an Infinitely wide Slider Bearing: An Application of the Finite-Element Method

1973 ◽  
Vol 15 (4) ◽  
pp. 311-320 ◽  
Author(s):  
A. K. Tieu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Equation ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Slider Bearing ◽  
Oil Film ◽  
Temperature Distributions ◽  
Oil Films ◽  
Element Method

From the Glansdorff–Prigogine local potential in non-equilibrium thermodynamics (1)† (2), a variational principle for a thin film incompressible flow with viscous dissipation is formulated as the basis of a finite-element method, which is applied to solve the energy equation. Temperature distributions in tapered land and parallel oil films for infinitely wide bearings are obtained by digital computer. The application of the finite-element method in a three-dimensional oil film with side leakage is also discussed.

Performance characteristics of two-axial groove journal bearing for different groove angles

2018 ◽  
Vol 70 (2) ◽  
pp. 432-443
Author(s):  
K.R. Kadam ◽  
S.S. Banwait
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Heat Conduction ◽  
Pressure Distribution ◽  
Heat Conduction Equation ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Content Type

Purpose Different groove angles are used to study performance characteristics of two-axial groove journal bearing. In this study two grooves are located at ±90º to the load line. The various angles of grooves have been taken as 10° to 40° in the interval of 5°. Different equations such as Reynolds equation, three-dimensional energy equation and heat conduction equation have been solved using finite element method and finite difference method. Pressure distribution in fluid is found by using Reynolds equation. The three-dimensional energy equation is used for temperature distribution in the fluid film and bush. One-dimensional heat conduction equation is used for finding temperature in axial direction for journal. There is a very small effect of groove angle on film thickness, eccentricity ratio and pressure. There is a drastic change in attitude angle and side flow. Result shows that there is maximum power loss at large groove angle. So the smaller groove angle is recommended for two-axial groove journal bearing. Design/methodology/approach The finite element method is used for solving Reynolds equation for pressure distribution in fluid. The finite difference method is adopted for finding temperature distribution in bush, fluid and journal. Findings Pressure distribution in fluid is found out. Temperature distribution in bush, fluid and journal is found out. There is a very small effect of groove angle on film thickness, eccentricity ratio and pressure. Research limitations/implications The groove angle used is from 10 to 40 degree. The power loss is more when angle of groove increases, so smaller groove angle is recommended for this study. Practical implications The location of groove angle predicts the distribution of pressure and temperature in journal bearing. It will show the performance characteristics. ±90° angle we will prefer that will get before manufacturing of bearing. Social implications Due to this study, we will get predict how the pressure and temperature distribute in the journal. It will give the running condition of bearing as to at what speed and load we will get the maximum temperature and pressure in the bearing. Originality/value The finite element method is used for solving the Reynolds equation. Three-dimensional energy equation is solved using the finite difference method. Heat conduction equation is also solved for journal. The C language is used. The code is developed in C language. There are different equations which depend on each other. The temperature is dependent on pressure viscosity of fluid, etc. so C code is preferred.

A Study of Elastohydrodynamic Lubrication of a Centrally Loaded 120° Arc Partial Bearing in Different Flow Regimes

1983 ◽  
Vol 197 (2) ◽  
pp. 97-108 ◽  
Author(s):  
S C Jain ◽  
R Sinhasan ◽  
D V Singh
Keyword(s):  
Elastic Deformation ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Elastohydrodynamic Lubrication ◽  
Performance Characteristics ◽  
The Finite Element Method ◽  
Elasticity Equations ◽  
Laminar And Turbulent Flow ◽  
Deformation Coefficient ◽  
Three Dimensional Elasticity

The elastic deformation of the bearing liner is considered in determining the static and dynamic performance characteristics of the centrally loaded 120° arc bearing for eccentricity ratio up to 0.8 and mean Reynolds number up to 7500. Using the finite element method, the pressure distribution in the fluid film and the elastic deformation in the bearing shell are obtained by solving the Reynolds equation and the three-dimensional elasticity equations iteratively. The performance characteristics of the bearing are computed for different values of the deformation coefficient which is a measure of the flexibility of the bearing shell. In addition, some results are also reported for laminar and turbulent flow conditions treating viscosity as a function of pressure.

Comparison of Conventional and Pontic Fixed Partial Dentures Over Implants Using the Finite Element Method: Three-Dimensional Analysis of Cortical and Medullary Bone Stress

2020 ◽  
Vol 46 (3) ◽  
pp. 175-181
Author(s):  
Marcelo Bighetti Toniollo ◽  
Mikaelly dos Santos Sá ◽  
Fernanda Pereira Silva ◽  
Giselle Rodrigues Reis ◽  
Ana Paula Macedo ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Medullary Bone ◽  
Principal Stresses ◽  
Bone Stress ◽  
Bone Damage ◽  
Rehabilitation System ◽  
Minimum Requirements

Rehabilitation with implant prostheses in posterior areas requires the maximum number of possible implants due to the greater masticatory load of the region. However, the necessary minimum requirements are not always present in full. This project analyzed the minimum principal stresses (TMiP, representative of the compressive stress) to the friable structures, specifically the vestibular face of the cortical bone and the vestibular and internal/lingual face of the medullary bone. The experimental groups were as follows: the regular splinted group (GR), with a conventional infrastructure on 3 regular-length Morse taper implants (4 × 11 mm); and the regular pontic group (GP), with a pontic infrastructure on 2 regular-length Morse taper implants (4 × 11 mm). The results showed that the TMiP of the cortical and medullary bones were greater for the GP in regions surrounding the implants (especially in the cervical and apical areas of the same region) but they did not reach bone damage levels, at least under the loads applied in this study. It was concluded that greater stress observed in the GP demonstrates greater fragility with this modality of rehabilitation; this should draw the professional's attention to possible biomechanical implications. Whenever possible, professionals should give preference to use of a greater number of implants in the rehabilitation system, with a focus on preserving the supporting tissue with the generation of less intense stresses.

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