A Three-Dimensional oil film Temperature Distribution in Tilting Thrust Bearings

1974 ◽  
Vol 16 (2) ◽  
pp. 121-124 ◽  
Author(s):  
A. K. Tieu

The oil film temperature and pressure distributions of the finite width Michell tilting thrust pad are determined from a numerical scheme based on the finite element method. These computed results correlate very well with those obtained from the experiment.

1975 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. K. Tieu

A variational principle for a thin-film incompressible flow with viscous dissipation has already been formulated as the basis of a finite-element analysis and applied to solve the oil-film energy equation for the case of infinitely wide thrust bearings (1)†. Here, the finite-element method is extended to a three-dimensional oil film, the pressure and temperature distributions of which agree very well with those obtained from other theoretical and experimental work. Allowance for various factors affecting thrust-pad performance, such as hot oil carry-over, rotor surface temperature and pad radial tilting, in the non-isoviscous bearing analysis has been shown to improve the agreement between numerical simulation and experiment.


2013 ◽  
Vol 318 ◽  
pp. 148-152
Author(s):  
Yao Yao Hong ◽  
Li Jun Du ◽  
She Miao Qi

The finite element method (FEM) is applied in the numerical simulation of heavy hydrostatic thrust bearings to study the influence of pressure and temperature on bearing deformation. The pressure distribution and the temperature distribution are obtained by solving the Reynolds equation and the energy equation. The bearing deformations caused by temperature and pressure are computed by imposing the two obtained distributions on the bearing. Because the pressure distribution and the temperature distribution are influenced by the oil film thickness and the oil film thickness is influenced by the bearing deformation, the numerical simulation is a process of iteration. The numerical results demonstrate that, in heavy hydrostatic thrust bearings, the thermal deformation and the mechanical deformation are both significant and can not be neglected. The influence of operation parameters on the anti-capsizing capability of heavy hydrostatic thrust bearings is also discussed. The obtained results reveal that, the anti-capsizing moment of the bearing increases with the decrease of the central thickness of the oil film.


1973 ◽  
Vol 15 (4) ◽  
pp. 311-320 ◽  
Author(s):  
A. K. Tieu

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.


1975 ◽  
Vol 97 (4) ◽  
pp. 577-584 ◽  
Author(s):  
A. K. Tieu

The three types of finite width thrust bearings, tilting pad, diaphragm tilting pad and diaphragm stepped pad, are simulated on the PDP-6 computer taking into account thermal effects on the oil film viscosity and the diaphragm deflection. The temperature boundary conditions of the three-dimensional oil film volume are obtained from the experiment described in Part I. The computed load carrying capacities of the three types of thrust bearings are compared with the experimental results, and quite good agreement between theory and experiment is obtained.


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 ◽  
...  

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.


1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.


Author(s):  
P.A. Radchenko ◽  
◽  
S.P. Batuev ◽  
A.V. Radchenko ◽  
◽  
...  

The fracture of high-strength impactor in interaction with a steel barrier is investigated. Three typesof head parts of the impactor are considered: flat, hemispherical and ogival. Normal and oblique interactions with velocities of 700 and 1000 m/s are investigated. Modeling is carried out by the finite element method in a three-dimensional formulation using the author's software EFES 2.0.The limit value of intensity of plastic deformations is used as a fracture criterion. The influence of the striker head part shape, interaction velocity, interaction angle on the fracture of the impactor and the barrier has been investigated. Conditions under which the striker ricochets were defined.


2014 ◽  
Vol 644-650 ◽  
pp. 1551-1555
Author(s):  
Jian Ming Zhang ◽  
Yong He

This paper is concerned with the convergence of the h-p version of the finite element method for three dimensional Poisson problems with edge singularity on quasi-uniform meshes. First, we present the theoretical results for the convergence of the h-p version of the finite element method with quasi-uniform meshes for elliptic problems on polyhedral domains on smooth functions in the framework of Jacobi-weighted Sobolev spaces. Second, we investigate and analyze numerical results for three dimensional Poission problems with edge singularity. Finally, we verified the theoretical predictions by the numerical computation.


1979 ◽  
Vol 24 (90) ◽  
pp. 489-490 ◽  
Author(s):  
J. J. Emery ◽  
E. A. Hanafy ◽  
G. H. Holdsworth ◽  
F. Mirza

Abstract The finite-element method is being used to simulate glacier flow problems, with particular emphasis on the surge behaviour of the Barnes Ice Cap, Baffin Island. Following an advanced feasibility study to determine the influence of major factors such as bed topography and flow relationships, a refined simulation model is being developed to incorporate realistically: the thermal regime of the ice mass; large deformations during flow and sliding; basal sliding zones; a temperature and stress dependent ice flow relationship; mass balance; and three-dimensional influences. The findings of the advanced feasibility study on isothermal, steady-state flow of the Barnes Ice Cap are presented in the paper before turning to a detailed discussion of the refined simulation model and its application to surging. It is clear that the finite-element method allows necessary refinements not available to analytical approaches.


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