scholarly journals Influence of piston ring profiles and oil temperature distribution on cylinder liner lubrication of a marine two-stroke engine

2019 ◽  
Vol 178 (3) ◽  
pp. 257-263
Author(s):  
Andrzej WOLFF
Keyword(s):  
Temperature Distribution ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Combustion Engines ◽  
Comprehensive Model ◽  
Piston Rings ◽  
Calculation Results ◽  
The Right ◽  
Stroke Engine ◽  
Selection Of

In the paper a comprehensive model of a piston-ring-cylinder (PRC) system has been presented. The local thickness of the oil film can be compared to height of the combined surface roughness of a cylinder liner and piston rings. Equations describing the mixed lubri-cation problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been ap-plied. The main parts of the model have been experimentally verified abroad by the author at the marine engine designing centre. In contrast to the previous papers of the author concerning the PRC system of combustion engines, new calculation results for a ma-rine two-stroke engine have been presented. Firstly the right selection of barrel-shaped sliding surface of piston rings has been analysed. Secondly the influence of oil temperature distribution along the cylinder liner on the lubrication of the PRC system has been assessed. The developed model and software can be useful for optimization of the PRC system design.

scholarly journals Modeling of piston ring wear

2020 ◽  
pp. 135065012092986
Author(s):  
Ana López Rodríguez ◽  
Anders Vølund ◽  
Peder Klit
Keyword(s):  
Piston Ring ◽  
Theoretical Study ◽  
Cylinder Liner ◽  
Ceramic Materials ◽  
Combustion Engines ◽  
Surface Wear ◽  
Piston Rings ◽  
Final Shape ◽  
Ring Geometry ◽  
Load Pattern

A theoretical study of piston ring wear in large two-stroke engines is presented. Piston rings in combustion engines are manufactured with an initially defined shape of the surface contacting the cylinder liner. Further the ring surface working against the cylinder liner is coated with layers of ceramic materials to accommodate the running-in process. Most rings have a nonflat shape (parabolic) when delivered from the ring supplier. After running in which is typically many hours of operation( >1000 h) the ceramic layers are worn and the ring geometry is typically changed significantly by surface wear. It is shown in the present study that the geometry of the worn ring depends on the operation scheme of the engine. Both the load pattern and the order in which the loads are applied influences the final shape of the piston ring surface.

scholarly journals Wear of different material pairings for the cylinder liner – piston ring contact

2018 ◽  
Vol 70 (4) ◽  
pp. 687-699 ◽  
Author(s):  
Thomas Wopelka ◽  
Ulrike Cihak-Bayr ◽  
Claudia Lenauer ◽  
Ferenc Ditrói ◽  
Sándor Takács ◽  
...  
Keyword(s):  
Steady State ◽  
Wear Mechanisms ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Wear Behaviour ◽  
Special Focus ◽  
Intermediate Step ◽  
Piston Rings ◽  
Content Type ◽  
Cylinder Liners

Purpose This paper aims to investigate the wear behaviour of different materials for cylinder liners and piston rings in a linear reciprocating tribometer with special focus on the wear of the cylinder liner in the boundary lubrication regime. Design/methodology/approach Conventional nitrided steel, as well as diamond-like carbon and chromium nitride-coated piston rings, were tested against cast iron, AlSi and Fe-coated AlSi cylinder liners. The experiments were carried out with samples produced from original engine parts to have the original surface topography available. Radioactive tracer isotopes were used to measure cylinder liner wear continuously, enabling separation of running-in and steady-state wear. Findings A ranking of the material pairings with respect to wear behaviour of the cylinder liner was found. Post-test inspection of the cylinder samples by scanning electron microscopy (SEM) revealed differences in the wear mechanisms for the different material combinations. The results show that the running-in and steady-state wear of the liners can be reduced by choosing the appropriate material for the piston ring. Originality/value The use of original engine parts in a closely controlled tribometer environment under realistic loading conditions, in conjunction with continuous and highly sensitive wear measurement methods and a detailed SEM analysis of the wear mechanisms, forms an intermediate step between engine testing and laboratory environment testing.

Field-Testing of Biodiesel (B100) and Diesel-Fueled Vehicles: Part 3—Wear Assessment of Liner and Piston Rings, Engine Deposits, and Operational Issues

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Deepak Agarwal
Keyword(s):  
Piston Ring ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Field Testing ◽  
Field Trials ◽  
Operating Conditions ◽  
Piston Rings ◽  
Carbon Deposits ◽  
Bottom Dead Center ◽  
Operational Issues

Abstract This study investigated the use of biodiesel (B100) and baseline mineral diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel’s compatibility and durability issues with modern common rail direct injection (CRDI) engine-powered vehicles. Two identical vehicles were operated for 30,000 km under identical operating conditions during a field-trial using biodiesel (B100) and mineral diesel. Exhaustive experimental results from this series of tests are divided into four sections, and this is the third paper of this series of four papers, which covers comparative feasibility and wear analyses, underlining the effect of long-term use of biodiesel on wear of cylinder liner and piston rings compared to baseline mineral diesel-fueled vehicle. Surface microstructures at three locations of the cylinder liner were evaluated using scanning electron microscopy (SEM). Wear was found to be relatively lower at all locations of liners from biodiesel-fueled vehicle compared to diesel-fueled vehicle. Surface roughness of cylinder liners measured at different locations showed that it reduced by ∼30–40% at top dead center (TDC), ∼10–20% at mid-stroke, and ∼20–30% at bottom dead center (BDC) for both vehicles, showing higher wear close to TDC compared to mid-stroke and BDC locations. Loss of piston-ring weight was significantly lower for biodiesel-fueled vehicle. Engine tear-down observations and carbon deposits on various engine components were recorded after the conclusion of the field trials. During these field-trials, engine durability-related issues such as fuel-filter plugging, injector coking, piston-ring sticking, carbon deposits in the combustion chamber, and contamination of lubricating oils were found to be relatively lower in biodiesel-fueled vehicle. Overall, no noticeable durability issues were recorded because of the use of biodiesel in CRDI engine-powered vehicle.

Simulation of Altitude Influence on Piston Ring Movement and Blow-By Effects in Piston Engines (Keynote)

2003 ◽  
Author(s):  
Sylvester Abanteriba
Keyword(s):  
Combustion Chamber ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Lubricating Oil ◽  
Axial Position ◽  
Piston Engine ◽  
Piston Rings ◽  
Ability To Act ◽  
Effective Seal ◽  
The Impact

The compression and oil rings of the piston engine play a very important role in the performance and reliability of the piston engine. The rings are required to accomplish three main distinct tasks: 1. Sealing the combustion chamber gas from the crankcase to eliminate blow-by phenomenon, which constitutes the flow of some of the contents of the combustion chamber into the crankcase. 2. Proper distribution of the lubricating oil film over the piston skirt and cylinder liner. 3. Transfer of heat from piston to cylinder liner. Unfortunately the piston ring pack contributes to the highest proportion of the frictional losses in the engine and is more prone to high wear rates. In the engine, the compression rings are designed to provide effective sealing of the crankcase against the gases from the combustion chamber. The oil-rings provide an effective means of distributing the lubricating oil over the cylinder liner while keeping it from flowing into the combustion chamber. The ability of the compression rings to serve as a gas seal depends on their axial position within the groove. The ring needs to be in contact with the lower flank in order to provide the requisite sealing effect. Once the ring lifts itself from the lower flank its ability to act as an effective seal is compromised. The axial motion of the piston rings during the operation of the engine engenders blow-by and therefore has deteriorating effect on the engine performance. Not much work has, hereto, been done to study the impact of altitude on the movement of the piston rings and hence the blow-by phenomenon. This papers presents a simulation model to investigate this effect.

An analytical study of tribological parameters between piston ring and cylinder liner in internal combustion engines

2016 ◽  
Vol 230 (4) ◽  
pp. 329-349 ◽  
Author(s):  
Mohamed Kamal Ahmed Ali ◽  
Hou Xianjun ◽  
Richard Fiifi Turkson ◽  
Muhammad Ezzat
Keyword(s):  
Film Thickness ◽  
Internal Combustion Engines ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Combustion Engines ◽  
Oil Viscosity ◽  
Oil Film ◽  
Ring Assembly ◽  
Ring Dynamics ◽  
Tribological Parameters

This paper presents a model to study the effect of piston ring dynamics on basic tribological parameters that affect the performance of internal combustion engines by using dynamics analysis software (AVL Excite Designer). The paramount tribological parameters include friction force, frictional power losses, and oil film thickness of piston ring assembly. The piston and rings assembly is one of the highest mechanically loaded components in engines. Relevant literature reports that the piston ring assembly accounts for 40% to 50% of the frictional losses, making it imperative for the piston ring dynamics to be understood thoroughly. This analytical study of the piston ring dynamics describes the significant correlation between the tribological parameters of piston and rings assembly and the performance of engines. The model was able to predict the effects of engine speed and oil viscosity on asperity and hydrodynamic friction forces, power losses, oil film thickness and lube oil consumption. This model of mixed film lubrication of piston rings is based on the hydrodynamic action described by Reynolds equation and dry contact action as described by the Greenwood–Tripp rough surface asperity contact model. The results in the current analysis demonstrated that engine speed and oil viscosity had a remarkable effect on oil film thickness and hydrodynamic friction between the rings and cylinder liner. Hence, the mixed lubrication model, which unifies the lubricant flow under different ring–liner gaps, is needed via the balance between the hydrodynamic and boundary lubrication modes to obtain minimum friction between rings and liner and to ultimately help in improving the performance of engines.

First Paper: Measurement of the Oil-Film Thickness between the Piston Rings and Liner of a Small Diesel Engine

1974 ◽  
Vol 188 (1) ◽  
pp. 253-261 ◽  
Author(s):  
G. M. Hamilton ◽  
S. L. Moore
Keyword(s):  
Diesel Engine ◽  
Film Thickness ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Piston Rings ◽  
Oil Film

A capacity gauge has been designed for operating in the conditions of a working engine. The method of using it for determining the oil-film thickness and piston-ring profile is described. Oil-film thicknesses in the range 0·4-2·5 μm between the piston rings and the cylinder liner have been observed. Their variation with speed, load and temperature has been measured and it is concluded that their behaviour is essentially hydrodynamic.

scholarly journals Mathematical Model of Piston Ring Sealing in Combustion Engine

2015 ◽  
Vol 21 (4) ◽  
pp. 66-78 ◽  
Author(s):  
Grzegorz Koszałka ◽  
Mirosław Guzik
Keyword(s):  
Mathematical Model ◽  
Heat Exchange ◽  
Numerical Solution ◽  
Gas Flow ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Computer Application ◽  
Piston Rings ◽  
Flow Through

Abstract This paper presents a mathematical model of piston-rings-cylinder sealing (TPC) of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The paper contains descriptions of: assumptions used for developing the model, the model itself, its numerical solution as well as its computer application for carrying out simulation tests.

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