Effects of Piston-Ring Dynamics on Ring/Groove Wear and Oil Consumption in a Diesel Engine

1997 ◽  
Author(s):  
Tian Tian ◽  
Remi Rabute ◽  
Victor W. Wong ◽  
John B. Heywood
Keyword(s):  
Diesel Engine ◽  
Piston Ring ◽  
Oil Consumption ◽  
Ring Groove ◽  
Ring Dynamics

The Dynamics of Second Ring Flutter and Collapse in Modern Diesel Engines

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Chao Cheng ◽  
Harold Schock ◽  
Dan Richardson
Keyword(s):  
Diesel Engine ◽  
Gas Flow ◽  
Piston Ring ◽  
Sensitivity Study ◽  
The Other ◽  
Heavy Duty ◽  
Oil Consumption ◽  
Ring Dynamics ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Second ring fluttering and radial ring collapse are recognized as having significant influences on engine blowby and oil consumption. As the gas flow is coupled with the piston ring motion, understanding the ring dynamics is important for understanding not only the engine blowby mechanism, but also oil consumption mechanisms and how to control them. Only second ring flutter and collapse that occurs around the top dead center (TDC) firing conditions is examined in this paper based on a modern heavy-duty diesel engine. However, the principles described are equally applicable to all engines. First, the authors describe the fundamental mechanisms of how second ring fluttering and radial ring collapse occur. This is described by examining the forces that are acting on the second ring. Then, two cases are shown. One case shows second ring flutter and the other case shows stable second ring motion. The reasons for these two different cases are explained, including the effect of static twist and the end gaps of the rings. A sensitivity study was performed to evaluate the effect of changing the top and second ring end gaps on ring lift. It was shown how the gaps could affect the second ring flutter and ring collapse. It is concluded that the second ring will be more likely to flutter or collapse if it has a negative static twist, if the second ring end gap is large, and/or if the top ring end gap is small. If the second ring does not flutter, it may still be possible to design the ring pack such that there is not any reverse blowby. However, this must be carefully studied and controlled or the second land pressures will be too high, resulting in reverse blowby and/or top ring lifting.

The Dynamics of Second Ring Flutter and Collapse in Modern Diesel Engines

2014 ◽  
Author(s):  
Chao Cheng ◽  
Harold Schock ◽  
Dan Richardson
Keyword(s):  
Diesel Engine ◽  
Gas Flow ◽  
Piston Ring ◽  
Sensitivity Study ◽  
The Other ◽  
Heavy Duty ◽  
Oil Consumption ◽  
Ring Dynamics ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Second ring fluttering and radial ring collapse are recognized as having significant influences on engine blowby and oil consumption. As the gas flow is coupled with the piston ring motion, understanding the ring dynamics is important for understanding not only the engine blowby mechanism, but also oil consumption mechanisms and how to control them. Only second ring flutter and collapse that occurs around the top dead center firing conditions is examined in this paper based on a modern heavy-duty diesel engine. However, the principles described are equally applicable to all engines. First, the authors describe the fundamental mechanisms of how second ring fluttering and radial ring collapse occurs. This is described by examining the forces that are acting on the second ring. Then, two cases are shown. One case shows second ring flutter and the other case shows stable second ring motion. The reasons for these two different cases are explained, including the effect of static twist and the end gaps of the rings. A sensitivity study was performed to evaluate the effect of changing the top and second ring end gaps on ring lift. It was shown how the gaps could affect the second ring flutter and ring collapse. It is concluded that the second ring will be more likely to flutter or collapse if it has a negative static twist, if the second ring end gap is large, and/or if the top ring end gap is small. If the second ring does not flutter, it may still be possible to design the ring pack such that there is not any reverse blowby. However, this must be carefully studied and controlled or the second land pressures will be too high, resulting in reverse blowby and/or top ring lifting.

Diesel Engine Oil Consumption Depending on Piston Ring Motion and Design

1993 ◽  
Author(s):  
Hideki Yoshida ◽  
Masaki Yamada ◽  
Hiroyuki Kobayashi
Keyword(s):  
Diesel Engine ◽  
Piston Ring ◽  
Engine Oil ◽  
Oil Consumption

Characterization of the Ring Pack Lubricant and its Environment

1995 ◽  
Vol 209 (2) ◽  
pp. 109-118 ◽  
Author(s):  
P J Burnett ◽  
B Bull ◽  
R J Wetton
Keyword(s):  
Internal Combustion Engines ◽  
Piston Ring ◽  
Combustion Engines ◽  
Oil Consumption ◽  
Ring Groove ◽  
Direct Sampling ◽  
Engine Wear ◽  
Ring Pack ◽  
Motion Characterization

The performance characteristics of the piston ring-liner assembly and the lubricant within it are critical for the operation of modern internal combustion engines. The ring pack can directly affect engine friction, oil consumption and oil degradation, which in turn can impact upon fuel economy, emissions and engine wear. The operation of this system is complex and no single technique is capable of fully characterizing the processes occurring. This paper outlines the range of both experimental and theoretical methods that are being applied to the study of this system and the lubricant within it. These include the modelling of ring pack gas and oil flows, and direct measurement of piston temperatures, ring belt pressures and piston ring motion. Characterization of lubricant degradation via direct sampling of oil from the top ring groove of an operating engine has also been used. The merits of such a multi-faceted approach are discussed in relation to piston deposit formation.

Diesel Engine Oil Consumption Depending on Piston Ring Design

1991 ◽  
Author(s):  
Hideki Yoshida ◽  
Kazunori Kusama ◽  
Hiroyuki Kobayashi
Keyword(s):  
Diesel Engine ◽  
Piston Ring ◽  
Engine Oil ◽  
Oil Consumption

scholarly journals Analysis and Optimization Study of Piston in Diesel Engine Based on ABC-OED-FE Method

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Qi Jing ◽  
Yi Dong ◽  
Jianmin Liu ◽  
Huaying Li ◽  
Yanbin Liu ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Artificial Bee Colony ◽  
Piston Ring ◽  
Maximum Stress ◽  
Geometric Parameters ◽  
Stress Fields ◽  
Maximum Temperature ◽  
Orthogonal Experimental Design ◽  
Ring Groove ◽  
Bee Colony

In order to increase the reliability and service life of piston in a heavy-duty diesel engine, the geometric structure of piston was optimized based on its maximum temperature and maximum coupling stress. To begin with, the boundary conditions of thermal and stress fields are calculated, which include the heat produced by the combustion in cylinder, the friction-induced heat, and the heat transferred to cooling system. Then, the finite element model was established to calculate and analyse the temperature and thermal-mechanical coupling stress fields of the piston. By combining this simulation model with orthogonal experimental design methods, computations and analyses were performed to determine how the five geometric parameters (depth of intake and exhaust valve grooves, radius of valve grooves transition, radius of top of valve grooves, height of first piston ring groove, and depth of piston ring groove) influence the two evaluation indicators (maximum temperature and maximum stress of piston). Subsequently, using the proposed ABC-OED- FE (artificial bee colony, orthogonal experiment design, and fitting equations) method, the fitting equations between the geometric parameters and evaluation indicators were determined. Taking the minimum values of two evaluation indicators of piston as optimization objectives, artificial bee colony method was run to determine the values of parameters. At last, the two evaluation indicators of the optimized piston were computed. The results indicate that, after optimization, the maximum temperature of piston decreases to be 16.05 K and the maximum stress decreases to be 13.54 MPa. Both temperature and stress conditions of the optimized piston had been improved, which demonstrates the effectiveness of the optimization and the validity of the algorithm.

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