Numerical Analysis of a Slider Bearing with a Heterogeneous Slip/No-Slip Surface

Abstract

The behavior of a fluid-film bearing depends on the boundary conditions at the interfaces between the liquid and the solid bearing surfaces. For almost all solid surfaces, the no-slip boundary condition applies. However, a number of researchers have recently found that slip can occur with specially engineered surfaces. These include molecularly smooth surfaces and surfaces with micron-scale patterns. By constructing an engineered heterogeneous surface on which slip occurs in certain regions and is absent in others, the flow in the liquid film of a bearing can be altered, and such characteristics as load support and friction can be improved. In the present study, a numerical analysis of a slider bearing with such an engineered slip/no-slip surface is analyzed. Slip is assumed to occur when a critical shear stress is exceeded and follows the Navier relation. The results show that with a critical shear stress of zero, a significant increase in load support and decrease in friction can be achieved with an appropriate surface pattern. With nonzero values of critical shear stress, an instability occurs over a range of speeds. At speeds above this range, the bearing behaves similar to the case with zero critical shear stress, while below this range it behaves like a conventional bearing.

Keywords:

• Fluid-Film Bearings
• Hydrodynamic Bearings

ACKNOWLEDGMENTS

The support of the Taiho Kogyo Tribology Research Foundation and the Georgia Power Company is gratefully acknowledged.

Presented at the 59th STLE Annual Meeting in Toronto, Ontario, Canada May 17-20, 2004

Final manuscript approved January 7, 2004

Review led by Luis San Andres