scholarly journals Role Of Computational Simulations In The Design Of Piston Rings

2015 ◽  
Vol 13 (1) ◽  
pp. 1-6
Author(s):  
Pavel Novotný ◽  
Peter Raffai ◽  
Jozef Dlugoš ◽  
Ondřej Maršálek ◽  
Jiří Knotek
Keyword(s):  
Piston Ring ◽  
Cylinder Liner ◽  
Si Engine ◽  
Piston Rings ◽  
Oil Film ◽  
Ring Solution ◽  
Film Formulation ◽  
Lubrication Conditions ◽  
Film Lubrication

Abstract The paper presents computational approaches using modern strategies for a dynamic piston ring solution as a fluid structural problem. Computational model outputs can be used to understand design parameter influences on defined results of a primarily integral character. Piston ring dynamics incorporates mixed lubrication conditions, the influence of surface roughness on oil film lubrication, the influence of ring movement on gas dynamics, oil film formulation on a cylinder liner and other significant influences. The solution results are presented for several parameters of SI engine piston rings.

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 Numerical analysis of piston ring pack operation

2009 ◽  
Vol 137 (2) ◽  
pp. 128-141
Author(s):  
Andrzej WOLFF
Keyword(s):  
Mathematical Model ◽  
Gas Flow ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Labyrinth Seal ◽  
Piston Rings ◽  
Oil Film ◽  
Piston Ring Pack ◽  
Ring Pack

In the paper a model of a piston ring pack motion on an oil film has been analysed. The local oil film thickness can be compared to height of the combined roughness of mating surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng [6, 7] and Greenwood, Tripp [3] have been combined [12] and used in this paper. A model of a gas flow through the labyrinth seal of piston rings has been developed [13, 15]. In addition models of ring twist effects and axial ring motion in piston grooves have been applied [14, 15]. In contrast to the previous papers of the author, an experimental verification of the main parts of developed mathematical model and software has been presented. A relatively good compatibility between the experimental measurements and calculated results has been achieved. In addition this study presents the simulation results for an automobile internal combustion engine

scholarly journals Experimental Study on the Effect of Marine Engine Lubricant Degradation on Tribological Performance of Cylinder Liner and Piston Rings Contact Using a Tuning Fork Technology Based Oil Sensor

2019 ◽  
Author(s):  
M Anand ◽  
M Hadfield ◽  
JL Viesca ◽  
B Thomas
Keyword(s):  
Boundary Lubrication ◽  
Piston Ring ◽  
Tuning Fork ◽  
Cylinder Liner ◽  
Tribological Performance ◽  
Gas Pressure ◽  
Piston Rings ◽  
Marine Engine ◽  
Marine Engines ◽  
Lubrication Conditions

An investigation was carried out to study the effect of changes in oil quality on its tribological performance using a tuning fork technology based oil sensor. In this research, a tribological testing system was commissioned, to simulate the piston ring-cylinder liner sliding contact, and to measure the lubricant condition in real-time using an oil sensor. Tribological contact between cylinder liners and piston rings in marine engines is the most affected region due to excessive thermo-mechanical stresses. At top dead centre, the effect of such stresses is at a maximum where piston-sliding speed is lowest, while the temperature is high due to fuel combustion, and radial load behind the piston rings compressing against the cylinder liner surface is at a maximum due to gas pressure and the compression fit of piston rings within the cylinder liner. At bottom dead centre, this effect is less severe due to a reduction in temperature and gas pressure on the piston rings, as the piston is positioned away from the combustion chamber. These two regions experience boundary lubrication conditions, where anti-wear and anti-friction additives are responsible for forming a protective lubricious film on sliding surfaces. At mid-stroke, piston-sliding speed is maximum, therefore, a full hydrodynamic film is formed in this region separating the piston rings and cylinder liner. The formation of oil film depends upon, the physical properties of oil (such as viscosity and density) under hydrodynamic lubrication conditions, and the oil chemistry (such as presence of additives in oil) under mixed or boundary lubrication conditions. Lubricants in marine engines undergo intense degradation in quality due to contamination with wear particles, water, soot, un-burnt fuel, coolant, and additives depletion. Such degradation of lubricants leads to a reduction in their capability to form a minimum thickness of oil film between two moving engine components to avoid direct metal-to-metal contact, which may cause wear. Therefore, monitoring the condition of marine engine lubricants is vital in order to predict any significant change in its quality. The results obtained from tribology testing and oil condition monitoring in the current research showed a good correlation and are useful to understand the performance of lubricants for piston ring-liner contacts.

scholarly journals Influence of piston ring pack configuration on blowby and friction losses in a marine two-stroke engine

2017 ◽  
Vol 170 (3) ◽  
pp. 164-170
Author(s):  
Andrzej WOLFF
Keyword(s):  
Gas Flow ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Labyrinth Seal ◽  
Piston Rings ◽  
Marine Engine ◽  
Oil Film ◽  
Flow Through ◽  
Piston Ring Pack ◽  
Ring Pack

In the paper a comprehensive model of a piston ring pack motion on an oil film 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 lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been combined and used in this paper. In addition a model of gas flow through the labyrinth seal of piston rings has been developed. The main parts of the model and software have been experimentally verified abroad by the author at the marine engine designing centre. For the selected two-stroke marine engine, the influence of the number of piston rings used and the type of the top ring lock (straight or overlapped) on blowby to piston underside and on friction losses of the piston-ring-cylinder (PRC) system have been investigated. The developed model and software can be useful for optimization of the PRC system design

Analysis of Tribological Performance of Piston Ring Lubrication

2011 ◽  
Author(s):  
Yibin Guo ◽  
Wanyou Li ◽  
Dequan Zou ◽  
Xiqun Lu ◽  
Tao He
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Power Loss ◽  
Piston Ring ◽  
Design Parameters ◽  
Oil Film ◽  
Starved Lubrication ◽  
Piston Ring Lubrication ◽  
Cylinder Bore ◽  
Lubrication Conditions

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.

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.

Wear Properties and Scuffing Resistance of the Cr–Al2O3 Coated Piston Rings: The Effect of Convexity Position on Barrel Surface

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Siqi Ma ◽  
Wenbin Chen ◽  
Chengdi Li ◽  
Mei Jin ◽  
Ruoxuan Huang ◽  
...  
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Surface Morphology ◽  
Pressure Distribution ◽  
Cylinder Liner ◽  
Wear Loss ◽  
Wear Properties ◽  
Piston Rings ◽  
Oil Film ◽  
Influencing Mechanism

This work investigates the effect of convexity position of ring barrel surface on the wear properties and scuffing resistance of the Cr–Al2O3 coated piston rings against with the CuNiCr cast iron cylinder liner. The scuffed surface morphology and elements distribution as well as the oil film edge were analyzed to explore the influencing mechanism of the convexity position on the scuffing resistance. The results show that the convexity offset rate on the barrel surface of the ring has no noticeable influence on both friction coefficient and wear loss near the dead points, but a suitable convexity position will result in the improved scuffing resistance. The shape of the barrel face not only affects the worn area on the ring, but also determines the oil film wedge and pressure distribution, consequently influences the scuffing resistance.

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.

Numerical Simulation on the Lubrication Performance of Surface Textured Piston Rings

2011 ◽  
Vol 199-200 ◽  
pp. 734-738 ◽  
Author(s):  
Qiu Ying Chang ◽  
Xian Liang Zheng ◽  
Qing Liu
Keyword(s):  
Numerical Simulation ◽  
Film Thickness ◽  
Friction Force ◽  
Friction And Wear ◽  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Area Density ◽  
Oil Film ◽  
Lubrication Performance

Surface texturing has been successfully employed in some tribological applications in order to diminish friction and wear. This technology may be used in a piston ring to decrease the friction and wear of the contact between a piston ring and cylinder liner. A numerical simulation of lubrication between a surface textured piston ring and cylinder liner based on the hydrodynamic lubrication theory was conducted. The influence of surface texture parameters on piston ring lubrication performance was obtained by solving the mathematical equations with a multi-grid method. The results show that under the micro-dimple area density of 5%-40% the minimum oil film thickness increases and the dimensionless friction force decreases with the increasing of it. Under the dimple area density of 40%-60%, the minimum oil film thickness and the dimensionless friction force change slightly. Under various dimple area densities the optimum dimple depth at the given working condition in this paper is about 5µm.

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