Friction Predictions for Piston Ring-Cylinder Liner Lubrication

2004 ◽  
Author(s):  
H. Xu ◽  
M. D. Bryant ◽  
R. D. Matthews ◽  
T. M. Kiehne ◽  
B. D. Steenwyk ◽  
...  
Keyword(s):  
Piston Ring ◽  
Cylinder Liner ◽  
Operating Conditions ◽  
Bench Test ◽  
Real Surface ◽  
Test Rig ◽  
Film Rupture ◽  
Restoring Force ◽  
Lubrication Regimes ◽  
Lubrication Models

This paper presents two piston ring and cylinder liner lubrication models and compares the friction predictions against the experimental results from a corresponding bench test. The first model aims to solve the average Reynolds equation with corrective flow factors, which describe the influence of surface irregularities on the lubricant flow under mixed lubrication condition. The second model takes account of the lubricant film rupture and cavitation. Meanwhile, a stochastic rough contact sub-model quantifies the relation between contact pressure and mean surface separation in both cases. Numerical results on the top compression ring simulation show that both models capture hydrodynamic, mixed, and boundary lubrication regimes, which depend on the real surface topographies of the piston ring and the cylinder liner. Whenever hydrodynamic action is insufficient to maintain the equilibrium position of the ring, the restoring force will be augmented by multi-asperity contacts lubricated by a thin boundary film. Total friction will originate mainly from shearing of viscous lubricant and shearing of asperity conjunctions. The purpose of this modeling effort is to compare both lubrication models to data from an experimental test-rig. This test rig eliminates many of the factors that can make analysis of predictions for real engine operating conditions difficult.

Experimental Piston Ring Tribology for Marine Diesel Engines

2008 ◽  
Author(s):  
Peder Klit ◽  
Anders Vo̸lund
Keyword(s):  
Piston Ring ◽  
Real Life ◽  
Cylinder Liner ◽  
Operating Conditions ◽  
Test Apparatus ◽  
Important Condition ◽  
Frictional Behavior ◽  
Lubrication Regimes ◽  
Oil Distribution ◽  
Marine Diesel

A very important condition for describing the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. It is often assumed that piston rings operate under fully flooded conditions, but this is not the case in real life operation. In large two-stroke engines the cylinder oil is supplied periodically to the bearing at discrete locations on the cylinder liner. The shifting in lubrication regimes and the non-uniform oil distribution opens for the possibility of starved conditions for the piston ring bearing. Therefore it is important to measure the oil distribution on the liner as a function of the operating conditions. The amount of lubricant available is reflected in the friction absorbed in the bearing. The paper describes an investigation of the tribological condition between a piston ring and cylinder. A test apparatus is used to study the interaction between a piston ring and a cylinder liner.

A Spectrographic Sampling Method for Quick Assessment of Cylinder and Piston Ring Wear

1968 ◽  
Vol 90 (1) ◽  
pp. 43-48
Author(s):  
H. U. Wisniowski ◽  
D. R. Jackson
Keyword(s):  
Rapid Method ◽  
Sampling Method ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Small Sample ◽  
Operating Conditions ◽  
Small Hole ◽  
Cylinder Wall ◽  
Lubricating Oils ◽  
Wear Rates

A simple, inexpensive, and rapid method of assessing cylinder and piston ring wear was developed. A small sample of the oil which lubricates the cylinder wall and piston rings was drawn off through a small hole in the cylinder wall. The sample was then analyzed spectrographically. Changes in wear resulting from changes in cylinder liner materials, fuels, lubricating oils, and other operating conditions were investigated. The method was found useful especially in cases of drastic differences in the wear rates. Selected examples of these studies are reported.

Mutual influence of plateau roughness and groove texture of honed surface on frictional performance of piston ring–liner system

2016 ◽  
Vol 231 (7) ◽  
pp. 838-859 ◽  
Author(s):  
Yang Hu ◽  
Xianghui Meng ◽  
Youbai Xie ◽  
Jiazheng Fan
Keyword(s):  
Piston Ring ◽  
Cylinder Liner ◽  
Texture Features ◽  
Groove Depth ◽  
Mixed Lubrication ◽  
Operating Conditions ◽  
Friction Reduction ◽  
Lubrication Performance ◽  
Liner System ◽  
Frictional Performance

The cylinder liner surface finish, which is commonly produced using the honing technique, is an essential factor of engine performance. The characteristics of the texture features, including the cross-hatch angle, the plateau roughness and the groove depth, significantly affect the performance of the ring pack–cylinder liner system. However, due to the influence of the honed texture features, the surface roughness of the liner is not subject to Gaussian distribution. To simulate the mixed lubrication performance of the ring–liner system with non-Gaussian roughness, the combination of a two-scale homogenization technique and a deterministic asperities contact method is adopted. In this study, a one-dimensional homogenized mixed lubrication model is established to study the influence of groove parameters on the load-carrying capacity and the frictional performance of the piston ring–liner system. The ring profile, plateau roughness, and operating conditions are taken into consideration. The main findings are that for nonflat ring, shallow and wide groove textures are beneficial for friction reduction, and there exists an optimum groove density that makes the friction minimum; for flat ring, wide and sparse grooves help improving the tribological performance, and there exists an optimum groove depth that makes the friction minimum.

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.

Theoretical Analysis of Piston Ring Frictional Loss in an Innovative Rotating Liner Internal Combustion Engine

2005 ◽  
Author(s):  
H. Xu ◽  
M. Kim ◽  
M. D. Bryant ◽  
R. D. Matthews ◽  
T. M. Kiehne
Keyword(s):  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Rolling Friction ◽  
Friction Model ◽  
Statistical Parameters ◽  
Restoring Force ◽  
Frictional Loss ◽  
Surface Irregularities ◽  
Liner Surface

This paper presents a new lubrication model to predict piston ring friction. The average Reynolds equation is adopted to obtain the hydrodynamic component of restoring force against the cylinder liner surface. The dry or boundary lubricated component is derived from Greenwood-Tripp model. The influence of surface irregularities or roughness on the lubricant flow will be described by statistical parameters. Unlike classical piston ring mixed lubrication models, a sideslip rolling friction model is incorporated with contact simulation. Numerical results show that piston ring friction is reduced dramatically by the liner rotation.

Advanced Tribological Assessment of Ring Coatings

2012 ◽  
Author(s):  
Max Maschewske ◽  
Kimm Karrip ◽  
Carol Lynn Deck
Keyword(s):  
Coefficient Of Friction ◽  
Surface Finish ◽  
Internal Combustion Engines ◽  
Gas Flow ◽  
Piston Ring ◽  
Friction Reduction ◽  
Bench Test ◽  
Test Rig ◽  
Frictional Characteristic ◽  
The Impact

Friction reduction within the power cylinder assembly of internal combustion engines continues to be a one of the foremost focuses of engine manufactures. In an effort to better address this topic previously developed bench test rigs, such as the Falex, Cameron-Plint, and EMA-LS9 [1,2], have been utilized. These devices were formerly focused solely on wear mechanisms and material compatibility. Current development of new piston ring coatings has demanded significant refinements to the previously mentioned EMA-LS9 test rig for specific frictional characteristic evaluations. These developments have allowed for coefficient of friction ranking between various piston ring materials in addition to the influence and surface finish on coefficient of friction. This paper examines how the test rig is utilized to characterize upper compression ring materials, surface treatments, and the impact of surface finish. The significance of these results will be examined as it applies to analytical evaluations. From these calculations a demonstration of the effect of surface finish on ring dynamics and gas flow, as well as future piston ring coating developments will be discussed.

Sign in / Sign up

Export Citation Format

Share Document