Thermal Elastohydrodynamic Lubrication of Rolling/Sliding Contacts

1990 ◽  
Vol 112 (2) ◽  
pp. 189-195 ◽  
Author(s):  
F. Sadeghi ◽  
P. C. Sui
Keyword(s):  
Finite Element ◽  
Temperature Effects ◽  
Energy Equation ◽  
Control Volume ◽  
Elastohydrodynamic Lubrication ◽  
Sliding Contacts ◽  
Simultaneous System ◽  
Elasticity Equations ◽  
Newton Raphson ◽  
Control Volume Finite Element

A complete numerical solution of thermal compressible elastohydrodynamic lubrication of rolling/sliding contacts has been obtained. The Newton-Raphson technique is used to solve the simultaneous system of Reynolds and elasticity equations. The control volume finite element modeling was employed to solve the energy equation and its boundary conditions. The effects of various loads, speeds, and slip conditions on the lubricant temperature, film thickness, and friction force have been investigated. The results indicate that the temperature effects are significant and cannot be neglected.

Thermal Elastohydrodynamic Lubrication of Rough Surfaces

1990 ◽  
Vol 112 (2) ◽  
pp. 341-346 ◽  
Author(s):  
F. Sadeghi ◽  
Ping C. Sui
Keyword(s):  
Energy Equation ◽  
Control Volume ◽  
Rough Surfaces ◽  
Elastohydrodynamic Lubrication ◽  
Radius Of Curvature ◽  
Transient Effects ◽  
Heavy Load ◽  
Elasticity Equations ◽  
Ehd Lubrication ◽  
Control Volume Finite Element

A numerical solution to the problem of thermal and compressible elastohydrodynamic (EHD) lubrication of rolling/sliding rough surfaces was obtained by neglecting the transient effects. The technique involves the simultaneous solution of thermal Reynolds and modified elasticity equations using the Newton-Raphson technique, and the energy equation using the control volume finite element method. The effects of various loads, amplitude of asperity, and radius of curvature of asperity have been investigated. Results have been presented for moderate dimensionless load of W = 9.03 × 10−5 to heavy load of W = 2.3 × 10−4 at the speed of U* = 9.2 × 10−11. The results indicate that surface roughness significantly affect the pressure, temperature, and traction in EHD lubrication.

Compressible Elastohydrodynamic Lubrication of Rough Surfaces

1989 ◽  
Vol 111 (1) ◽  
pp. 56-62 ◽  
Author(s):  
F. Sadeghi ◽  
Ping C. Sui
Keyword(s):  
Numerical Solution ◽  
Rough Surfaces ◽  
Roughness Parameter ◽  
Elastohydrodynamic Lubrication ◽  
Surface Pattern ◽  
Simultaneous System ◽  
Elasticity Equations ◽  
Newton Raphson ◽  
Compression Effects

A complete numerical solution of compressible elastohydrodynamic lubrication of rough surfaces has been obtained. The Newton-Raphson technique is used to solve the simultaneous system of modified compressible Reynolds and elasticity equations. The effects of various loads, surface pattern, and roughness parameter have been investigated. Results have been presented for loads ranging from W = 2.0452 × 10−5 to W = 2.3 × 10−4 at the speed of U = 1.0 × 10−11. The results indicate that the compression effects are significant and cannot be neglected.

Prediction of Permeability Tensor for Plain Woven Fabric by Using Control Volume Finite Element Method

2003 ◽  
Vol 11 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Y. S. Song ◽  
K. Chung ◽  
T. J. Kang ◽  
J. R. Youn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Control Volume ◽  
Three Dimensional ◽  
Woven Fabrics ◽  
Permeability Tensor ◽  
Woven Fabric ◽  
Stacking Order ◽  
Control Volume Finite Element ◽  
Element Method

The complete prediction of the second order permeability tensor for a three dimensional multi-axial preform is critical if we are to model and design the manufacturing process for composites by considering resin flow through a multi-axial fiber structure. In this study, the in-plane and transverse permeabilities for a woven fabric were predicted numerically by the coupled flow model, which combines microscopic and macroscopic flows. The microscopic and macroscopic flows were calculated by using 3-D CVFEM(control volume finite element method) for micro and macro unit cells. To avoid a checkerboard pressure field and improve the efficiency of numerical computation, a new interpolation function for velocity is proposed on the basis of analytical solutions. The permeability of a plain woven fabric was measured by means of an unidirectional flow experiment and compared with the permeability calculated numerically. Reverse and simple stacking of plain woven fabrics were taken into account and the relationship between the permeability and the structures of the preform such as the fiber volume fraction and stacking order is identified. Unlike other studies, the current study was based on a more realistic three dimensional unit cell. It was observed that in-plane flow is more dominant than transverse flow within the woven perform, and the effect of the stacking order of a multi-layered preform was negligible.

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