Effect of Coating and Low Viscosity Oils on Piston Ring Friction under Mixed Regime of Lubrication through Analytical Modelling

Madey

et al. 2022

JMSE

In this study, a method for ensuring reliable and safe operation of marine trunk diesel engines is considered. The research was carried out on 5L23/30 MAN-B&W diesel engines of a Bulk Carrier class vessel. The objective of the study was to determine the effect of the structural characteristics of the oil layer (wetting angle and thickness) on the operational parameters of a marine diesel engine (compression pressure, concentration of nitrogen oxides in exhaust gases and temperature of exhaust gases after the cylinder) and performance characteristics of the oil (base number, wear and contaminant elements). It has been established that an increase in the degree of the contact angles of wetting and in the thickness of the oil layer improves the heat and power and environmental performance of a diesel engine. At the same time, the decrease in compression pressure in the cylinder slows down, the temperature of gases after the cylinder decreases, and the emission of nitrogen oxides with exhaust gases decreases. Also, it was found that wear of diesel parts and oil oxidation are reduced. The study confirms the possibility of improving the reliable and safe operation of trunk-type diesel engines of maritime vessels by effective control of variables relating to the characteristics of engine oil.

Section: Literature Reviewmentioning

confidence: 99%

Ensuring Reliable and Safe Operation of Trunk Diesel Engines of Marine Transport Vessels

Madey

et al. 2022

JMSE

“…2). An increase in the contact angles of wetting both on the open surface (at the metaloilair phase boundary) and between the surfaces (at the metaloilmetal phase boundary) contributes to an increase in the surface tension force, a decrease in oil leakage, and an increase in the bearing capacity of the oil layer [9,16,17]. TECHNOLOGY AUDIT AND PRODUCTION RESERVES -№ 5/1(67), 2022 ISSN 2664-9969…”

Section: The Object Of Research and Its Technological Auditmentioning

confidence: 99%

Analysis of the operation of marine diesel engines when using engine oils with different structural characteristics

Stoliaryk

2022

TAPR

The object of research is the process of lubrication of marine trunk diesel engines. The subject of research is marine diesel engine oils, which provide lubrication, cooling and separation of friction surfaces. The analysis of the operation of marine diesel engines using motor oils with different structural characteristics is carried out. The studies are carried out on Yanmar 6EY18AL diesel engines of a Multipurpose Vessel class ship with deadweight of 27540 tons. The objective of research is to determine the effect of the structural characteristics of the oil layer (contact angle and thickness) on the performance parameters of a marine diesel engine and the performance characteristics of the oil used in its circulating lubrication system. At the same time, the compression pressure, the concentration of nitrogen oxides in the exhaust gases, and the temperature of the exhaust gases after the cylinder are considered as the operating parameters of the diesel engine; as performance characteristics of the oil – its Base Number, as well as its Wear and Contaminant Elements. The studies are carried out on two diesel engines of the same type, in the circulating lubrication system of which oils with different structural characteristics were used. Structural characteristics of the oil layer were determined by ellipsometry. The operational characteristics of the diesel engine – using the Doctor diagnostic system. Oil performance – by spectrographic analysis. It has been established that an increase in the contact angles of wetting and the thickness of the oil layer improves the heat and power and environmental performance of a diesel engine. At the same time (for the period of operation of diesel engines 500–1000 hours), the decrease in compression pressure in the cylinder slows down, the temperature of gases after the cylinder decreases, and the emission of nitrogen oxides with exhaust gases decreases. In addition, the wear of diesel parts and oil oxidation are reduced. The information obtained in the course of the study on the structural characteristics of motor oils will provide the possibility of their selection and further use of those that will contribute to a better maintenance of the operational performance of marine diesel engines.

Tribology - Materials, Surfaces & Interfaces

“…This is valid for surfaces with a layer of ferrous oxide [44]. However, the effect of surface morphology and lubricant is predominant in this value [7]. Therefore, a detailed analysis using measured surface properties for ring and liner components [45], as well as the lubricant properties should be further studied.…”

Section: Theorymentioning

confidence: 99%

“…The contact in the ring-bore mechanism is the most complex owing to the variation of lubrication regimes (boundary, mixed and full-hydrodynamic). Analytical methods were studied for the ring-liner conjunction by Akalin et al [5], Hamatake et al [6] and Zavos [7]. They modelled the basic lubrication theory of Reynolds within the contact using different engine conditions.…”

Section: Introductionmentioning

confidence: 99%

On the influence of axial cylinder distortions on lubricant film and friction force of top piston ring conjunction near to TDC

Nikolakopoulos

Antonakakis

Zavos

2022

Self Cite

The purpose of this paper was to understand how axial cylinder distortions influence the tribological performance of piston ring. The current model contains the effects of axial distortions and ring conformability under mixed to hydrodynamic regimes of lubrication through computational fluid dynamics predictions. The axial cylinder profiles were modelled using series of sinusoidal waves. The effect of axial distortions on ring wear rate was determined using the Archard's model. The ring friction and minimum lubricant film were predicted for low and high combustion pressures near to top dead centre. The study shows that, when the maximum combustion pressure rises, the different wear identities affect the operation of the ring friction much more limited, while the number of sine waves are more pronounced. Finally, it is proved that, even the increase of oil film thickness, it does not presuppose the reduction of friction when it comes to shaping the surface of the cylinder liner.