A Numerical Solution of the Thermal Elastohydrodynamic Lubrication in an Elliptical Contact

1982 ◽  
Vol 104 (3) ◽  
pp. 392-400 ◽  
Author(s):  
H. Bru¨ggemann ◽  
F. G. Kollmann

A numerical solution for the calculation of thickness and temperature of film and traction coefficients between heavily loaded elliptical contact is developed. To start the calculation a Hertzian pressure distribution modified at the inlet and outlet regions is assumed and the surface deformations are calculated. The Navier-Stokes equations and the energy equation are simultaneously solved by the finite difference method. The pressure distribution introduced is verified with the help of the condition of continuity and, if necessary, corrected. The dependence of the viscosity and the density of the lubricant on pressure and temperature is determined by empirical equations which are derived from experimental data. A time dependency of the viscosity is allowed for high viscosities. The distribution of temperature in the film is obtained for a selected example. The thicknesses of the oil film and the traction coefficients are compared with experimental results.

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1603-1614
Author(s):  
Martin Scholtysik ◽  
Bernhard Mueller ◽  
Torstein K. Fannelop

Author(s):  
Cheng-Hsien Chen ◽  
Yuan Kang ◽  
Yeon-Pun Chang ◽  
De-Xing Peng ◽  
Ding-Wen Yang

This paper studies the influences of recess geometry and restrictor dimensions on the flow patterns and pressure distribution of lubricant film, which are coupled effects of hybrid characteristics of a hydrostatic bearing. The lubricant flow is described by using the Navier-Stokes equations. The Galerkin weighted residual finite element method is applied to determine the lubricant velocities and pressure in the bearing clearance. The numerical simulations will evaluate the effects of the land-width ratio and restriction parameter as well as the influence of modified Reynolds number and the jet-strength coefficient on the flow patterns in the recess and pressure distribution in lubricant film. On the basis of the simulation drawn from this study, the simulated results are expected to help engineers make better use of the design of hydrostatic bearing and its restrictors.


1995 ◽  
Vol 1 (3-4) ◽  
pp. 225-235 ◽  
Author(s):  
M. J. Braun ◽  
M. Dzodzo

The flow in a hydrostatic pocket is numerically simulated using a dimensionless formulation of the 2-D Navier-Stokes equations written in primitive variables, for a body fitted coordinates system, and applied through a collocated grid. In essence, we continue the work of Braun et al. 1993a, 1993b] and extend it to the study of the effects of the pocket geometric format on the flow pattern and pressure distribution. The model includes the coupling between the pocket flow and a finite length feedline flow, on one hand, and the pocket and its adjacent lands on the other hand. In this context we shall present, on a comparative basis, the flow and the pressure patterns at the runner surface for square, ramped-Rayleigh step, and arc of circle pockets. Geometrically all pockets have the same footprint, same lands length, and same capillary feedline. The numerical simulation uses the Reynolds number based on the lid(runner) velocity and the inlet jet strengthFas the dynamic similarity parameters. The study aims at establishing criteria for the optimization of the pocket geometry in the larger context of the performance of a hydrostatic bearing.


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