The role of cylinder bore shapes in engine performance has been the subject of several studies in recent years. In particular, the influence of bore distortion on oil consumption under high speed conditions has generated significant interest. In this paper, the effect of an axial bore profile on radial dynamics of a ring is investigated. Radial ring motions within grooves due to the axial bore profile can generate significant inertial effects and also have an impact on ring end-gap sizes and lubrication conditions at the ring-liner interfaces. The magnitude of such effects is dependent on the ring-pack configuration, engine operating conditions (speed and load) and axial bore profile details. These issues are investigated in this study due to their implication on engine oil consumption, friction and blow-by. The authors have developed an analytical expression to account for the effects of radial ring inertia due to an axial bore profile for implementation in a piston ring-pack simulation tool RINGPAK. Simulation results from a gasoline engine study are presented to illustrate the effects of engine speeds, ring tensions, and characteristics of axial bore profiles on ring radial dynamics and ring-liner lubrication. Relevant qualitative comparisons are made to experimental measurements available in the literature.

1.
Takiguchi, M., Watanabe K., Kato, T., Sato, M., and Ueno, H., 1999, “Effects of Piston Ring Tension on Oil Consumption and Piston Friction in Diesel Engines,” ASME ICE Spring Technical Conference, Vol. 32-3, Paper No. 99-ICE-199.
2.
Hill, S. H., Kantola, T. C., Brown, J. R., and Hamelink, J. C., 1995, “An Experimental Study of the Effect of Cylinder Bore Finish on Engine Oil Consumption,” SAE Paper No. 950938.
3.
Schneider, E. W., Blossfeld, D. H., Lechman, D. C., Hill, R. F., Reising, R. F., and Brevick, J. E., 1993, “Effect of Cylinder Bore Out-of-Roundness on Piston Ring Rotation and Engine Oil Consumption,” SAE Paper No. 93796.
4.
Hitosugi, H. et al., 1996, “Study on Mechanism of Lubricating Oil Consumption Caused by Cylinder Bore Deformation,” SAE Paper No. 960305.
5.
Goto, T., Arai, T., Goto, T., and Hamai, K., 1989, “Influence of Cylinder Bore Distortion on Engine Performances (Part 1: Static Mode Analysis of Bore Distortion for Amount of Oil Consumption,” JSAE Paper No. 891010.
6.
Basaki, M., Saito, K., Nakashima, T., and Suzuki, T., 2000, “Analysis of Oil Consumption at High Engine Speed by Visualization of the Piston Ring Behaviors,” SAE Paper No. 2000-01-2877.
7.
Gulwadi
,
S. D.
,
1998
, “
A Mixed Lubrication and Oil Transport Model for Piston Rings Using a Mass-Conserving Algorithm
,”
ASME J. Eng. Gas Turbines Power
,
120
, pp.
199
208
.
8.
Gulwadi
,
S. D.
,
2000
, “
Analysis of Tribological Performance of a Piston Ring Pack
,”
Tribol. Trans.
,
43-2
, pp.
151
162
.
9.
Greenwood
,
J. A.
, and
Tripp
,
J. H.
,
1971
, “
The Contact of Two Nominally Flat Rough Surfaces
,”
Proc. Inst. Mech. Eng.
,
185
, pp.
625
633
.
10.
Piao, Y., and Gulwadi, S. D., 2000, “Effect of Piston Secondary Motion on the Numerical Modeling of Ring Pack Performance,” ASME-ICE Fall Technical Conference, ICE-Vol. 35-3, Paper No. 2000-342.
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