An alternative average Reynolds equation for use under conditions of large fractional contact area is proposed. The flow factors for this form of the equation are calculated for a variety of longitudinal surfaces and the results are shown to be relatively insensitive to the initial height distribution. Pressure and shear flow factors for the Christensen height distribution and a variety of Peklenik surface pattern parameters are also derived from the work of Patir and Cheng, Lo and Tripp. These are represented by semi-empirical equations over the full range of contact conditions. The implications of the results, with respect to the lubrication of metal forming processes, is discussed.

1.
Christensen
H.
,
1970
, “
Stochastic Models for Hydrodynamic Lubrication of Rough Surfaces
,”
Proc. Inst. of Mech. Engrs.
, Vol.
184
, pp.
1013
1022
.
2.
Lo
S. W.
,
1994
, “
A Study on Flow Phenomena in Mixed Lubrication Regime by Porous Media Model
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
116
, pp.
640
647
.
3.
Patir
N.
and
Cheng
H. S.
,
1978
, “
An Average Flow Model for Determining Effects of Three-Dimensional Roughness on Partial Hydrodynamic Lubrication
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
100
, pp.
12
17
.
4.
Peklenik
J.
,
1968
, “
New Developments in Surface Characterization and Measurements by Means of Random Process Analysis
,”
Proc. Inst. of Mech. Engrs.
, Vol.
182-3K
, pp.
108
126
.
5.
Tripp
J. H.
,
1983
, “
Surface Roughness Effects in Hydrodynamic Lubrication-The Flow Factor Method
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
105
, pp.
458
465
.
6.
Wilson, W. R. D. and Chang, D-F., 1994, Tribology in Manufacturing Processes, K, Dohda S. Jahanmir and W. R. D. Wilson, eds, pp. 159–168, ASME, New York, also to be published in ASME JOURNAL OF TRIBOLOGY.
7.
Wilson
W. R. D.
, and
Sheu
S.
,
1988
, “
Real Area of Contact and Boundary Friction in Metal Forming
,”
Int. J. of Mechanical Sci.
, Vol.
30
, No.
7
, pp.
475
489
.
This content is only available via PDF.
You do not currently have access to this content.