Numerical solution of mixed elastohydrodynamic lubrication (EHL) is of great importance for the study of lubrication formation and breakdown, as well as surface failures of mechanical components. However, converged and accurate numerical solutions become more difficult, and solution process with a fixed single discretization mesh for the solution domain appears to be quite slow, especially when the lubricant films and surface contacts coexist with real-machined roughness involved. Also, the effect of computational mesh density is found to be more significant if the average film thickness is small. In the present study, a set of sample cases with and without machined surface roughness are analyzed through the progressive mesh densification (PMD) method, and the obtained results are compared with those from the direct iteration method with a single fixed mesh. Besides, more numerical analyses with and without surface roughness in a wide range of operating conditions are conducted to investigate the influence of different compound modes in order to optimize the PMD procedure. In addition, different initial conditions are used to study the effect of initial value on the behaviors of this transient solution. It is observed that, no matter with or without surface roughness considered, the PMD method is stable for transient mixed EHL problems and capable of significantly accelerating the EHL solution process while ensuring numerical accuracy.

References

References
1.
Ranger
,
A. P.
,
Ettles
,
C. M. M.
, and
Cameron
,
A.
,
1975
, “
The Solution of the Point Contact Elastohydrodynamic Problem
,”
Proc. R. Soc., London A
,
346
, pp.
227
244
.
2.
Hamrock
,
B. J.
, and
Dowson
,
D.
,
1976
, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts—Part 1: Theoretical Formulation
,”
ASME J. Lubr. Technol.
,
98
(
2
), pp.
223
229
.
3.
Hamrock
,
B. J.
, and
Dowson
,
D.
,
1976
, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts—Part 2: Ellipticity Parameter Results
,”
ASME J. Lubr. Technol.
,
98
(
3
), pp.
375
383
.
4.
Hamrock
,
B. J.
, and
Dowson
,
D.
,
1977
, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts—Part 3: Fully Flooded Results
,”
ASME J. Lubr. Technol.
,
99
(
2
), pp.
264
276
.
5.
Evans
,
H. P.
, and
Snidle
,
R. W.
,
1981
, “
Inverse Solution of Reynolds Equation of Lubrication Under Point Contact Elastohydrodynamic Conditions
,”
ASME J. Lubr. Technol.
,
103
(
4
), pp.
539
546
.
6.
Evans
,
H. P.
, and
Snidle
,
R. W.
,
1982
, “
The Elastohydrodynamic Lubrication of Point Contacts at Heavy Loads
,”
Proc. R. Soc. A
,
382
(
1782
), pp.
183
199
.
7.
Zhu
,
D.
, and
Wen
,
S. Z.
,
1984
, “
A Full Numerical Solution for the Thermoelasto-Hydrodynamic Problem in Elliptical Contacts
,”
ASME J. Tribol.
,
106
(
2
), pp.
246
254
.
8.
Lubrecht
,
A. A.
,
1987
, “
The Numerical Solution of Elastohydrodynamic Lubricated Line and Point Contact Problems Using Multigrid Techniques
,” Ph.D. thesis, University of Twente, Enschede, The Netherlands.
9.
Venner
,
C. H.
,
1991
, “
Multilevel Solution of EHL Line and Point Contact Problems
,” Ph.D. thesis, University of Twente, Enschede, The Netherlands.
10.
Kim
,
K. H.
, and
Sadeghi
,
F.
,
1992
, “
Three Dimensional Temperature Distribution in EHD Lubrication—Part I: Circular Contact
,”
ASME J. Tribol.
,
114
(
1
), pp.
32
41
.
11.
Ai
,
X. L.
,
1993
, “
Numerical Analyses of Elastohydrodynamically Lubricated Line and Point Contacts With Rough Surfaces By Using Semi-System and Multigrid Methods
,” Ph. D. thesis, Northwestern University, Evanston, IL.
12.
Zhu
,
D.
, and
Ai
,
X. L.
,
1997
, “
Point Contact EHL Based on Optically Measured 3-Dimensional Rough Surfaces
,”
ASME J. Tribol.
,
119
(
3
), pp.
375
384
.
13.
Venner
,
C. H.
, and
Lubrecht
,
A. A.
,
2000
, “
Multilevel Methods in Lubrication
,”
Elsevier Tribology Series
, Vol.
37
,
Elsevier
,
Amsterdam
.
14.
Zhu
,
D.
, and
Hu
,
Y. Z.
,
1999
, “
The Study of Transition From Full Film Elastohydrodynamic to Mixed and Boundary Lubrication
,”
The Advancing Frontier of Engineering Tribology, 1999 STLE/ASME H. S. Cheng Tribology Surveillance, STLE, Park Ridge, IL
, pp.
150
156
.
15.
Hu
,
Y. Z.
, and
Zhu
,
D.
,
2000
, “
A Full Numerical Solution to the Mixed Lubrication in Point Contacts
,”
ASME J. Tribol.
,
122
(
1
), pp.
1
9
.
16.
Morales-Espejel
,
G. E.
,
Dumont
,
M. L.
,
Lugt
,
P. M.
, and
Olver
,
A. V.
,
2005
, “
A Limiting Solution for the Dependence of Film Thickness on Velocity in EHL Contacts With Very Thin Films
,”
Tribol. Trans.
,
48
(
3
), pp.
317
324
.
17.
Zhu
,
D.
,
2005
, “
Written Discussion on: A Limiting Solution for the Dependence of Film Thickness on Velocity in EHL Contacts With Very Thin Films
,”
Tribol. Trans.
,
48
(
3
), pp.
324
326
.
18.
Venner
,
C. H.
,
2005
, “
EHL Film Thickness Computations at Low Speeds: Risk of Artificial Trends as a Result of Poor Accuracy and Implications for Mixed Lubrication Modeling
,”
Proc. Inst. Mech. Eng., Part J
,
219
(
4
), pp.
285
290
.
19.
Liu
,
Y. C.
,
Wang
,
Q.
,
Wang
,
W. Z.
,
Hu
,
Y. Z.
, and
Zhu
,
D.
,
2006
, “
Effects of Differential Scheme and Mesh Density on EHL Film Thickness in Point Contacts
,”
ASME J. Tribol.
,
128
(
3
), pp.
641
653
.
20.
Zhu
,
D.
,
2007
, “
On Some Aspects in Numerical Solution of Thin-Film and Mixed EHL
,”
Proc. Inst. Mech. Eng., Part J
,
221
(
5
), pp.
561
579
.
21.
Liu
,
S. B.
,
Wang
,
Q.
, and
Liu
,
G.
,
2000
, “
A Versatile Method of Discrete Convolution and FFT (DC-FFT) for Contact Analyses
,”
Wear
,
243
(
1–2
), pp.
101
111
.
22.
Wang
,
W. Z.
,
Wang
,
H.
,
Liu
,
Y. C.
,
Hu
,
Y. Z.
, and
Zhu
,
D.
,
2003
, “
A Comparative Study of the Methods for Calculation of Surface Elastic Deformation
,”
Proc. Inst. Mech. Eng., Part J
,
217
(
2
), pp.
145
153
.
23.
Zhu
,
D.
,
Liu
,
Y.
, and
Wang
,
Q.
,
2014
, “
On the Numerical Accuracy of Rough Surface EHL Solution
,”
Tribol. Trans.
,
57
(
4
), pp.
570
580
.
24.
Lubrecht
,
A. A.
, and
Venner
,
C. H.
,
1999
, “
Elastohydrodynamic Lubrication of Rough Surfaces
,”
Proc. Inst. Mech. Eng., Part J
,
213
(
5
), pp.
397
404
.
25.
Mourier
,
L.
,
Mazuyer
,
D.
,
Lubrecht
,
A. A.
, and
Donnet
,
C.
,
2006
, “
Transient Increase of Film Thickness in Micro-Textured EHL Contacts
,”
Tribol. Int.
,
39
(
12
), pp.
1745
1756
.
26.
Zhu
,
D.
, and
Hu
,
Y. Z.
,
2001
, “
Effects of Rough Surface Topography and Orientation on the Characteristics of EHD and Mixed Lubrication in Both Circular and Elliptical Contacts
,”
Tribol. Trans.
,
44
(
3
), pp.
391
398
.
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