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 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.

scholarly journals An improved contact model considered the effect of boundary lubrication regime on piston ring-liner contact for the two-stroke marine engines from the perspective of the Stribeck curve

2021 ◽  
pp. 095440622110272
Author(s):  
Lyu Xiuyi ◽  
Bowen Jiao ◽  
Yuechang Wang ◽  
Abdullah Azam ◽  
Xiqun Lu ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Boundary Lubrication ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Work Conditions ◽  
Stribeck Curve ◽  
Regime Transition ◽  
Lubrication Regime ◽  
Lubrication Performance ◽  
Marine Engines

The prediction of lubrication performance is required to be the basement of friction optimization for marine engines. This paper simulates the lubrication performance of marine engines based on statistical models which have the advantages of fast, efficient, and macroscopic fault location. Boundary lubrication exists in the piston ring-cylinder liner (PRCL) of two-stroke marine engines because of the harsher load, lower speed, and larger structure. It has been proposed that there would be tribofilm under boundary lubrication which has a significant influence on the contact. To understand the boundary lubrication, it is necessary to study the lubrication regime transition. In this paper, firstly, the coefficient of friction curve combined with the thickness ratio embodies the lubrication regime transition process of two-stroke engines under work conditions. However, the phenomenon that the coefficients under boundary lubrication are smaller than that of other regimes shows the non-objectivity of this curve. Therefore, the Stribeck curve is introduced for objectively evaluating the transition. Then, the calculation of asperities contact pressure under boundary lubrication, which Wen proposed, is introduced into the classic Greenwood-Williamson model, the problem that the original model cannot reflect the boundary lubrication regime in the form of the Stribeck curve is improved. Finally, the results are compared before and after modifying the model to verify this study’s practicability. It provides more precise asperities contact pressure for the tribofilm growth calculation from the perspective of the Stribeck curve under the PRCL statistical model in future work.

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

Tribological performance of three surface-modified piston rings matched with chromium-plated cylinder liner

2017 ◽  
Vol 69 (2) ◽  
pp. 276-281 ◽  
Author(s):  
Feng Zhu ◽  
Jiujun Xu ◽  
Xiaoguang Han ◽  
Yan Shen ◽  
Mei Jin
Keyword(s):  
Piston Ring ◽  
Cylinder Liner ◽  
Tribological Performance ◽  
Wear Depth ◽  
Wear Properties ◽  
Piston Rings ◽  
Ic Engine ◽  
Content Type ◽  
Friction And Wear Properties ◽  
Surface Modified

Purpose The paper aims to investigate the friction and wear properties of three surface-modified piston rings matched with a chromium-plated cylinder liner. Design/methodology/approach Samples were taken from the chromium-plated cylinder liner, Cr-Al2O3 ring, CrN ring and Mo ring. Tribo-tests were conducted on a reciprocating sliding tribometer under fully formulated engine oils. Friction coefficients and wear depths of three friction pairs were tested. Surface morphologies of cylinder liners and piston rings before and after test were analyzed. Findings Experimental results show that in the Cr-Al2O3 piston ring, scuffing occurred easily when matched with the chromium-plated cylinder liner; compared with the Mo ring, the CrN ring could decrease the wear depth of the piston ring from 2.7 to 0.2 μm, and the wear depth of cylinder liner remained; however, the friction coefficient increased from 0.113 to 0.123. The tribological performances of three surface-modified piston rings were significantly different when they matched with chromium-plated cylinder liner. Originality/value Chromium-plated cylinder liner and the three kinds of surface-modified piston rings have excellent friction and wear properties, respectively. However, according to the systematic characteristics of internal combustion (IC) engine tribology, only the appropriate cylinder liner–piston ring can improve the tribological performance of the IC engine. This paper reports the tribological performance of three surface-modified piston rings matched with a chromium-plated cylinder liner. The results can be used as reference for the design of high-power-density diesel engine.

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.

Tribological evaluation of piston skirt/cylinder liner contact interfaces under boundary lubrication conditions

2010 ◽  
Vol 22 (3) ◽  
pp. 73-87 ◽  
Author(s):  
Nicholaos G. Demas ◽  
Robert A. Erck ◽  
George R. Fenske
Keyword(s):  
Boundary Lubrication ◽  
Cylinder Liner ◽  
Piston Skirt ◽  
Lubrication Conditions

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.

Influence of positive texturing on friction and wear properties of piston ring-cylinder liner tribo pair under lubricated conditions

2019 ◽  
Vol 71 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Venkateswara Babu P. ◽  
Ismail Syed ◽  
Satish Ben Beera
Keyword(s):  
Wear Resistance ◽  
Internal Combustion Engine ◽  
Friction And Wear ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Tribological Performance ◽  
Friction Reduction ◽  
Content Type

Purpose In an internal combustion engine, piston ring-cylinder liner tribo pair is one among the most critical rubbing pairs. Most of the energy produced by an internal combustion engine is dissipated as frictional losses of which major portion is contributed by the piston ring-cylinder liner tribo pair. Hence, proper design of tribological parameters of piston ring-cylinder liner pair is essential and can effectively reduce the friction and wear, thereby improving the tribological performance of the engine. This paper aims to use surface texturing, an effective and feasible method, to improve the tribological performance of piston ring-cylinder liner tribo pair. Design/methodology/approach In this paper, influence of positive texturing (protruding) on friction reduction and wear resistance of piston ring surfaces was studied. The square-shaped positive textures were fabricated on piston ring surface by chemical etching method, and the experiments were conducted with textured piston ring surfaces against un-textured cylinder liner surface on pin-on-disc apparatus by continuous supply of lubricant at the inlet of contact zone. The parameters varied in this study are area density and normal load at a constant sliding speed. A comparison was made between the tribological properties of textured and un-textured piston ring surfaces. Findings From the experimental results, the tribological performance of the textured piston ring-cylinder liner tribo pair was significantly improved over a un-textured tribo pair. A maximum friction reduction of 67.6 per cent and wear resistance of 81.6 per cent were observed with textured ring surfaces as compared to un-textured ring surfaces. Originality/value This experimental study is helpful for better understanding of the potency of positive texturing on friction reduction and wear resistance of piston ring-cylinder liner tribo pair under lubricated sliding conditions.

Effects of different surface grooved cylinder liner on the tribological performance for cylinder liner-piston ring components

2019 ◽  
Vol 72 (5) ◽  
pp. 581-588
Author(s):  
Jiazhi Miao ◽  
Yongqing Li ◽  
Xiang Rao ◽  
Libao Zhu ◽  
Zhiwei Guo ◽  
...  
Keyword(s):  
Piston Ring ◽  
Critical Factor ◽  
Cylinder Liner ◽  
Content Type ◽  
Crucial Effect ◽  
Design And Manufacturing ◽  
Marine Engines ◽  
Marine Diesel ◽  
Energy Economy ◽  
Groove Texture

Purpose The emission from marine engines has a crucial effect on energy economy and environment pollution. One of the effective emission reduction schemes is to minimize the friction loss of main friction pairs such as cylinder liner-piston ring (CLPR). Micro-groove textures were designed to accomplish this aim. Design/methodology/approach The authors experimentally investigated the effects of micro-groove textures at different cylinder liner positions. The micro-groove texture was fabricated on samples by chemical etching and cut from the real CLPR pair. Sliding contact tests were conducted by a reciprocation test apparatus. Findings The average friction coefficient of grooves at 30° inclination were reduced up to 58.22% and produced better tribological behavior at most conditions. The operating condition was the critical factor that determined the optimum texture pattern. The surface morphology indicated that textures could produce smoother surfaces and less scratches as compared with the untextured surface. Originality/value Inclined grooves and V-grooves were designed and applied to real CLPR pairs. The knowledge obtained in this study will lead to practical basis for tribological design and manufacturing of CLPR pair in marine diesel engines.

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