Next Article in Journal / Special Issue
Modeling the Fatigue Wear of the Cylinder Liner in Internal Combustion Engines during the Break-In Period and Its Impact on Piston Ring Lubrication
Previous Article in Journal
Surface Energy and Tribology of Electrodeposited Ni and Ni–Graphene Coatings on Steel
Previous Article in Special Issue
Modelling Transitions in Regimes of Lubrication for Rough Surface Contact
Open AccessArticle

Effect of Viscosity and Speed on Oil Cavitation Development in a Single Piston-Ring Lubricant Assembly

Department of Mechanical Engineering and Aeronautics, City, University of London, London EC1V 0HB, UK
*
Author to whom correspondence should be addressed.
Lubricants 2019, 7(10), 88; https://doi.org/10.3390/lubricants7100088
Received: 23 August 2019 / Revised: 27 September 2019 / Accepted: 27 September 2019 / Published: 9 October 2019
(This article belongs to the Special Issue Tribology of Powertrain Systems)
A high-speed camera has been used to produce unique time-resolved images of high quality to describe the dynamics of the lubricant flow and cavitation characteristics in a sliding optical liner over a fixed single piston-ring lubricant assembly for three lubricants with different viscosities to establish their impact on cavitation formation and development. The images were obtained at two cranking speeds (or liner sliding velocity) of 300 rpm (0–0.36 m/s) and 600 rpm (0–0.72 m/s), at a lubricant temperature of 70 °C and a supply lubricant rate of 0.05 L/min. A special MATLAB programme has been developed to analyse the cavitation characteristics quantitatively. The dynamic process of cavities initiation was demonstrated by time-resolved images from fern cavity formation to fissure cavities and then their development to the sheet and strings cavities at a liner sliding velocity of around 0.17 m/s. The results for both up- and down-stroke motions showed that the cavities reach their fully developed state downstream of the contact point when the liner velocity reaches its highest velocity and that they start to collapse around TDC and BDC when the liner comes to rest. Within the measured range, viscosity had a great influence on length of cavities so that a decrease in viscosity (from Lubricant A to C) caused a reduction in length of cavities of up to 35% for Lubricant C. On the other hand, an increase in speed, from 300 rpm to 600 rpm, have increased the number of string cavities and also increased the length of cavities due to thicker oil film thickness with the higher speed. Overall, the agreement between the processed data by MATLAB and visualisation measurements were good, but further thresholds refinement is required to improve the accuracy. View Full-Text
Keywords: lubricant flow; optical single ring-liner interaction; high-speed visualisation; MATLAB analysis; cavitation development; viscosity effect lubricant flow; optical single ring-liner interaction; high-speed visualisation; MATLAB analysis; cavitation development; viscosity effect
Show Figures

Graphical abstract

MDPI and ACS Style

Nouri, J.M.; Vasilakos, I.; Yan, Y.; Reyes-Aldasoro, C.-C. Effect of Viscosity and Speed on Oil Cavitation Development in a Single Piston-Ring Lubricant Assembly. Lubricants 2019, 7, 88.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop