scholarly journals Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0181574 ◽  
Author(s):  
Cheng Liu ◽  
Yan-Jun Lu ◽  
Yong-Fang Zhang ◽  
Sha Li ◽  
Norbert Müller
Keyword(s):  
Numerical Study ◽  
Cylinder Liner ◽  
Compression Ring ◽  
Lubrication Performance ◽  
Liner System

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.

Numerical analysis of the effects of compression ring wear and cylinder liner deformation on the thermal mixed lubrication performance of ring-liner system

2018 ◽  
Vol 19 (2) ◽  
pp. 203 ◽  
Author(s):  
Cheng Liu ◽  
Yanjun Lu ◽  
Peng Wang ◽  
Yongfang Zhang ◽  
Yonggui Zhang ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Thermal Effect ◽  
Cylinder Liner ◽  
Mass Conservation ◽  
Asperity Contact ◽  
Friction Forces ◽  
Oil Film ◽  
Compression Ring ◽  
Lubrication Performance ◽  
Liner System

The lubrication performance of roughness compression ring-cylinder liner system (CRCL) with axial-asymmetric new/worn compression ring and out-of-round cylinder liner is studied in this paper. By considering the oil film thermal effect, cavitation phenomenon, and surface roughness, the energy equations, mass conservation Jacoboson-Floberg-Olsson (JFO) cavitation algorithm, generalized average Reynolds equation, and Greenwood-Tripp asperity contact model are employed to investigate the frictional behaviors of CRCL. The oil film thickness, friction forces, wear, and power loss of CRCL are investigated at various wear stages of compression ring. The effects of the magnitude of cylinder liner deformation on the frictional characteristics of CRCL are also analyzed with consideration of compression ring conformability. Numerical results show that the deformation of cylinder liner and the wear of compression ring have a significant influence on the lubrication performance. It also suggests that the oil film thermal effect should be considered in the numerical analysis to provide an accurate prediction on the frictional behaviors of CRCL.

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.

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.

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.

Numerical Study on the Tribological Performance of Ring/Liner System With Consideration of Oil Transport

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Cheng Liu ◽  
Yanjun Lu ◽  
Yongfang Zhang ◽  
Sha Li ◽  
Jianxiong Kang ◽  
...  
Keyword(s):  
Transport Model ◽  
Numerical Study ◽  
Great Influence ◽  
Cylinder Liner ◽  
Tribological Performance ◽  
Oil Consumption ◽  
Oil Supply ◽  
Oil Transport ◽  
Liner System ◽  
Lubrication Condition

The tribological performance of a compression ring-cylinder liner system (CRCL) is numerically studied. A thermal-mixed lubrication model is developed for the lubrication analysis of the CRCL with consideration of the cylinder liner deformation. An oil transport model coupled with a mass conservation cavitation algorithm is employed to predict the oil consumption and the transition between the fully flooded lubrication condition and starved lubrication condition. On this basis, the effects of the oil supply and cylinder liner deformation on the frictional characteristics are investigated under cold and warm engine conditions. The results show that the cylinder liner deformation and oil supply have great influence on the tribological performance of the CRCL. Better tribological performance and lower oil consumption can be obtained by reasonably controlling the oil supply.

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.

Transient Heat Transfer Simulation of the Coupling 3-D Moving Piston Assembly-Lubricant Film-Liner System

2006 ◽  
Author(s):  
Liu Zhien ◽  
Jiang Yankun ◽  
Chen Guohua ◽  
Yang Wanli
Keyword(s):  
Heat Transfer ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Heat Transfer Model ◽  
Lubricant Film ◽  
Transient Heat Transfer ◽  
Transfer Model ◽  
Friction Heat ◽  
Liner System ◽  
Piston Assembly

Transient heat transfer model of the coupling 3-D moving piston assembly-lubricant film-liner system is successfully developed for predicting the temperature distributions in the component system of internal combustion chamber, in which the effect of the friction heat generated at the piston ring/cylinder liner interfaces has been taken into account. The finite element method (FEM) is employed in the model for establishing the heat transfer relation among the moving piston assembly-lubricant film-cylinder liner. The 3-D discrete model of the coupling system is obtained by hypothesizing the lubricant film as 1-D thermal resistances and the friction heat as heat flux boundary conditions. The allocation and distribution model of friction heat on piston ring pack and liner are also established. The 3-D coupling heat transfer model has been used to analyze the heat transfer of a gasoline engine.

Improvement of Transient Heat Transfer Models for the Coupled 3-D Moving Piston Assembly-Liner System

2007 ◽  
Author(s):  
Yankun Jiang ◽  
Zhien Liu ◽  
Rolf D. Reitz ◽  
Zheling Dong ◽  
Xiaoming Ye
Keyword(s):  
Heat Transfer ◽  
Gasoline Engine ◽  
Sparse Matrix ◽  
Cylinder Liner ◽  
Heat Transfer Model ◽  
Transient Heat Transfer ◽  
Transfer Model ◽  
Piston Rings ◽  
Liner System ◽  
Piston Assembly

A transient heat transfer model for the coupling 3-D moving piston assembly-liner system has been successfully improved for predicting temperature distributions in the components of internal combustion engine chamber. In the model the effect of the 3-D friction heat generated at the piston ring/cylinder liner interfaces and the multi-dimensional lubricant film thickness between the piston rings and the liner has been taken into account. A directly coupled finite element method (FEM) is employed in the model for establishing the heat transfer relation among the moving piston assembly-cylinder liner components. A 3-D discrete model of the coupling system is formulated, which includes the piston rings, piston, liner and cylinder. Due to the complexity of the temperature stiffness matrix, a sparse matrix data structure is employed in the model to save the memory and calculation time. Finally, the 3-D coupling heat transfer model has been used to analyze heat transfer processes in a gasoline engine.

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