Experimental validation of a mixed-lubrication regime model for textured piston-ring-liner contacts
File(s)
Accepted version
Author(s)
Profito, FJ
Vladescu, S-C
Reddyhoff, T
Dini, D
Type
Journal Article
Abstract
Recent experiments have shown that automotive piston-liner friction may be reduced by up to 50 % if the surface of the liner is laser textured with certain configurations of micro-pockets. It is important to model this behavior to understand and optimize the friction reduction mechanisms that are occurring. However, until now, very few models that predict the lubrication performance of textured surfaces have been successfully validated against experimental data. This is because of the requirement for them to: (1) reproduce experimental configurations with a certain degree of fidelity, (2) conserve mass properly, and (3) account for transient, boundary lubrication conditions. To address this, the current paper presents a comparison between the results from a numerical model, which fulfils these criteria, and an experimental test rig operating under the same conditions. The mathematical modeling is based on the averaged Reynolds’ equation with Patir and Cheng’s flow factors and the p − θ Elrod–Adams mass-conserving cavitation model. Simultaneously to the fluid flow solution, the contact pressures that arise from the asperity interactions are also included into the calculations through the well-known stochastic Greenwood and Tripp model for rough contacts. The experimental data is produced using a reciprocating tribometer, whose contact conditions are closely controlled and accurately mimic those found in an automotive piston–liner conjunction. Data is presented in terms of friction force versus stroke angle, and the similarities and differences between the model and experiment are discussed.
Date Issued
2017-01-30
Date Acceptance
2016-07-13
Citation
Materials Performance and Characterization, 2017, 6 (2), pp.112-129
ISSN
2165-3992
Publisher
American Society for Testing and Materials
Start Page
112
End Page
129
Journal / Book Title
Materials Performance and Characterization
Volume
6
Issue
2
Copyright Statement
© 2017 by ASTM International (all rights reserved).
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Ford Motor Company
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/G026114/1
N/A
EP/N025954/1
Subjects
Science & Technology
Technology
Materials Science, Multidisciplinary
Materials Science
piston rings
surface texture
modeling
mixed lubrication
AVERAGE FLOW MODEL
HYDRODYNAMIC LUBRICATION
JOURNAL BEARINGS
SURFACE TEXTURE
FRICTION FORCE
STRIBECK CURVE
CAVITATION
SIMULATION
ROUGHNESS
Publication Status
Published
Date Publish Online
2017-01-30