Numerical Study of Piston Skirt-Liner Lubrication Considering the Effects of Deformation in Internal Combustion Engines

2012 ◽  
Author(s):  
Lipu Ning ◽  
Xianghui Meng ◽  
Youbai Xie
Keyword(s):  
Elastic Deformation ◽  
Internal Combustion Engines ◽  
Numerical Study ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Surface Geometry ◽  
Piston Skirt ◽  
Lubrication Performance ◽  
Liner System

This paper presents a comprehensive lubrication model for piston skirt-liner system of internal combustion engines. In the model it is included that the effects of the surface roughness, the piston skirt surface geometry, the piston pin offset, the crankshaft offset, and the lubricant viscosity on the piston secondary motion and lubrication performance. Especially, the effects of the thermal and the elastic deformation of the piston skirt and the cylinder liner, and the piston skirt deformations due to the combustion pressure and the piston axial inertia, are considered as the key task in this study. The results show that the combustion force, the working temperature and the piston axial inertia all play important roles in the piston-skirt lubrication. Also, considering the elastic deformation of the piston skirt and the cylinder liner is beneficial to the prediction of piston-skirt lubrication more accurately. The developed program in this study can provide a useful tool for the analysis of the piston-liner system lubrication problem.

scholarly journals Enhancing the Geometrical Performance Using Initially Conical Cylinder Liner in Internal Combustion Engines—A Numerical Study

2020 ◽  
Vol 10 (11) ◽  
pp. 3705
Author(s):  
Ahmad Alshwawra ◽  
Florian Pohlmann-Tasche ◽  
Frederik Stelljes ◽  
Friedrich Dinkelacker
Keyword(s):  
Internal Combustion Engines ◽  
Thermal Stresses ◽  
Numerical Study ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Friction Reduction ◽  
Cylindrical Shape ◽  
Combustion Engines ◽  
Cold State ◽  
The Impact

Reducing friction is an important aspect to increase the efficiency of internal combustion engines (ICE). The majority of frictional losses in engines are related to both the piston skirt and piston ring–cylinder liner (PRCL) arrangement. We studied the enhancement of the conformation of the PRCL arrangement based on the assumption that a suitable conical liner in its cold state may deform into a liner with nearly straight parallel walls in the fired state due to the impact of mechanical and thermal stresses. Combining the initially conical shape with a noncircular cross section will bring the liner even closer to the perfect cylindrical shape in the fired state. Hence, a significant friction reduction can be expected. For the investigation, the numerical method was first developed to simulate the liner deformation with advanced finite element methods. This was validated with given experimental data of the deformation for a gasoline engine in its fired state. In the next step, initially conically and/or elliptically shaped liners were investigated for their deformation between the cold and fired state. It was found that, for liners being both conical and elliptical in their cold state, a significant increase of straightness, parallelism, and roundness was reached in the fired state. The combined elliptical-conical liner led to a reduced straightness error by more than 50% compared to the cylindrical liner. The parallelism error was reduced by 60% to 70% and the roundness error was reduced between 70% and 80% at different liner positions. These numerical results show interesting potential for the friction reduction in the piston-liner arrangement within internal combustion engines.

Numerical Study of Piston Skirt-Liner Elastohydrodynamic Lubrication and Contact by the Multigrid Method

2010 ◽  
Author(s):  
Xianghui Meng ◽  
Youbai Xie
Keyword(s):  
Contact Problem ◽  
Internal Combustion Engines ◽  
Multigrid Method ◽  
Numerical Study ◽  
Elastohydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Piston Skirt ◽  
Liner System ◽  
Tribological Analysis ◽  
Quasi Newton

The cylinder liner-piston system of internal combustion engines is one of the key friction pairs running at the most rigor working conditions. Under the influence of elastohydrodynamic lubrication and contact between the piston skirt and the liner, the dynamic process of piston is a nonlinear and stiff problem difficult to be analyzed accurately and easily. To reach a stable and rapid convergence in analysis, the MEBDF method and the multigrid method are used to solve the piston-skirt elastohydrodynamic lubrication and contact problem. Firstly the solving process of the piston dynamics is analyzed based on the MEBDF method. Then the residual equations for the elastohydrodynamic lubrication pressure are built based on the multigrid method. And the solving method of the nonlinear residual equations is presented based on the quasi Newton-Raphson method. Finally the numerical simulation program is developed based on the MEBDF method and the multigrid method. The elastohydrodynamic lubrication and contact problem of the piston skirt-liner system is simply analyzed based on the simulation. The study in this paper can provide an effective method for tribological analysis and optimization of piston–liner system in the future.

Cavitation erosion and wear behaviour of a boron cast iron cylinder liner under bio-fuel conditions

RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79968-79970 ◽  
Author(s):  
Yufu Xu ◽  
Lulu Yao ◽  
Bin Zhang ◽  
Ka Tang ◽  
Bao Li ◽  
...  
Keyword(s):  
Cast Iron ◽  
Internal Combustion Engines ◽  
Cavitation Erosion ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Wear Behaviour ◽  
Combustion Engines ◽  
Near Future

The use of renewable bio-fuel in internal combustion engines is the trend for the near future.

scholarly journals The Analysis of Secondary Motion and Lubrication Performance of Piston considering the Piston Skirt Profile

2018 ◽  
Vol 2018 ◽  
pp. 1-27 ◽  
Author(s):  
Yanjun Lu ◽  
Sha Li ◽  
Peng Wang ◽  
Cheng Liu ◽  
Yongfang Zhang ◽  
...  
Keyword(s):  
Thermal Deformation ◽  
Work Performance ◽  
Cylinder Liner ◽  
Connecting Rod ◽  
Piston Skirt ◽  
Piston Cylinder ◽  
Lubrication Performance ◽  
Rod System ◽  
Liner System ◽  
Secondary Motion

The work performance of piston-cylinder liner system is affected by the lubrication condition and the secondary motion of the piston. Therefore, more and more attention has been paid to the secondary motion and lubrication of the piston. In this paper, the Jakobson-Floberg-Olsson (JFO) boundary condition is employed to describe the rupture and reformation of oil film. The average Reynolds equation of skirt lubrication is solved by the finite difference method (FDM). The secondary motion of piston-connecting rod system is modeled; the trajectory of the piston is calculated by the Runge-Kutta method. By considering the inertia of the connecting rod, the influence of the longitudinal and horizontal profiles of piston skirt, the offset of the piston pin, and the thermal deformation on the secondary motion and lubrication performance is investigated. The parabolic longitudinal profile, the smaller top radial reduction and ellipticities of the middle-convex piston, and the bigger bottom radial reduction and ellipticities can effectively reduce the secondary displacement and velocity, the skirt thrust, friction, and the friction power loss. The results show that the connecting rod inertia, piston skirt profile, and thermal deformation have important influence on secondary motion and lubrication performance of the piston.

scholarly journals Numerical study of the physical processes of gas leakage in the compression ring in diesel engines

2021 ◽  
Vol 2118 (1) ◽  
pp. 012016
Author(s):  
J A Pabón León ◽  
J P Rojas Suárez ◽  
M S Orjuela Abril
Keyword(s):  
Numerical Model ◽  
Internal Combustion Engines ◽  
Numerical Study ◽  
Cylinder Liner ◽  
Combustion Engines ◽  
Combustion Gases ◽  
Gas Leakage ◽  
Lubrication Film ◽  
Compression Ring ◽  
Complex Mathematical Model

Abstract In this research, the construction of a numerical model is proposed for the analysis of the friction processes and the thickness of the lubrication film present in the compression ring of internal combustion engines. The model is built using MATLAB software, and three load conditions are used as reference (2 Nm, 4 Nm, and 6 Nm) with a rotation speed of 3600 rpm, which correspond to a stationary single-cylinder diesel engine. Comparison between model estimates and experimental results show that the development model could predict the actual engine conditions. The deviation between the numerical model and the experimental data was 17%. It was shown that the increase in engine load causes a 16% increase in the friction force of the compression ring, which implies a 50% increase in power loss due to friction processes. In general, the model developed allows the analysis of the friction processes in the compression ring and its effect on the lubrication film, considering the leakage of the combustion gases. In this way, the construction of a more complex mathematical model is achieved, which allows improving the precision in the analyzes related to the interaction between the compression ring and the cylinder liner.

scholarly journals Modeling the Fatigue Wear of the Cylinder Liner in Internal Combustion Engines during the Break-In Period and Its Impact on Piston Ring Lubrication

Lubricants ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 89
Author(s):  
Chongjie Gu ◽  
Renze Wang ◽  
Tian Tian
Keyword(s):  
Internal Combustion Engines ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Asperity Contact ◽  
Combustion Engines ◽  
Fatigue Wear ◽  
Wear Model ◽  
Surface Finishes ◽  
Liner Surface ◽  
Piston Ring Lubrication

In internal combustion engines, a significant portion of the total fuel energy is consumed to overcome the mechanical friction between the cylinder liner and the piston rings. The engine work loss through friction gradually reduces during the engine break-in period, as the result of liner surface topography changes caused by wear. This work is the first step toward the development of a physics-based liner wear model to predict the evolution of liner roughness and ring pack lubrication during the break-in period. Two major mechanisms are involved in the wear model: plastic deformation and asperity fatigue. The two mechanisms are simulated through a set of submodels, including elastoplastic asperity contact, crack initiation, and crack propagation within the contact stress field. Compared to experimental measurements, the calculated friction evolution of different liner surface finishes during break-in exhibits the same trend and a comparable magnitude. Moreover, the simulation results indicate that the liner wear rate or duration of break-in depends greatly on the roughness, which may provide guidance for surface roughness design and manufacturing processes.

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