Friction Analysis for Piston Ring of Seal Device in the Stirling Engine

To solve the practical problem of Stirling engine piston ring, numerical model on friction and lubrication were established based on average Reynolds equation theory. Numerical calculation results show: piston rings are in the mixed lubrication state which gas lubrication film and micro-convex body contact existing simultaneously; contact pressure is 2 orders of magnitude less than gas film pressure; contact pressure is approximately linearly related to mean gas pressure. Simulated test rig was built and experimental results show: high-pressure working gas leak to intermediate chamber through piston rings, and the pressure of intermediate chamber drops sharply at lowest pressure of circulation; piston ring wear increases when rotational speed or working pressure increase. The accuracy of numerical model was proved by experimental phenomena and test data.

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Three-Dimensional Hydrodynamic Lubrication Analysis of Cylinder Liner-Piston Ring

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.871.27 ◽

2013 ◽

Vol 871 ◽

pp. 27-31

Author(s):

Shi Feng Zhang ◽

Shu Hua Cao ◽

Jiu Jun Xu

Keyword(s):

Piston Ring ◽

Reynolds Equation ◽

Variable Viscosity ◽

Hydrodynamic Lubrication ◽

Three Dimensional ◽

Cylinder Liner ◽

Asperity Contact ◽

Crank Angle ◽

Minimum Film Thickness ◽

Friction Analysis

This paper constructs a three-dimensional transient hydrodynamic lubrication model for cylinder liner-piston ring based on the three-dimensional transient average Reynolds equation and asperity contact model. A computer program was written with FORTRAN to calculate hydrodynamic lubrication, in which the surface roughness, the variable viscosity effect and the deformation of the circumferential direction of the cylinder liner are taken into account. The film pressure distribution in different crank angle during the stroke, minimum film thickness and friction are computed and analyzed with this program. This three-dimensional transient hydrodynamic lubrication model provides a design basis for the friction analysis of cylinder liner-piston ring.

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The Analysis of the Influencing Factors about Friction and Wear Characteristics of the Piston Ring in Stirling Engine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2003 ◽

2013 ◽

Vol 690-693 ◽

pp. 2003-2007

Author(s):

Dong Ya Yang ◽

Huan Xie ◽

Jun Gong

Keyword(s):

Influencing Factors ◽

Life Prediction ◽

Friction And Wear ◽

Piston Ring ◽

Prediction Method ◽

Stirling Engine ◽

Gas Pressure ◽

Calculation Formula ◽

Wear Characteristics ◽

Friction And Wear Characteristics

The problem about friction and wear characteristics of piston ring which is directly related to the sealing properties of stirling engine was analyzed. An improved seal structure of piston ring was taken as the research object, the influence of the temperature and the pressure of refrigerant were considered when the friction and wear characteristics of piston ring in stirling engine was studied. The calculation formula about radial weal amount of the piston ring with the change of the temperature and the gas pressure was derived by using the peeling wear theory. Then, the experiment was taken to confirm these formulas. The results show that the formulas were right. Hence, a viable way to analysis the sealing properties and life prediction method of piston rings was got.

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Stirling engine

AccessScience ◽

10.1036/1097-8542.656300 ◽

2015 ◽

Keyword(s):

Stirling Engine

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Predictive tool for frictional performance of piston ring-pack/liner conjunction

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.13.3.2019.19.0445 ◽

2019 ◽

Vol 13 (3) ◽

pp. 5513-5527

Author(s):

J. W. Tee ◽

S. H. Hamdan ◽

W. W. F. Chong

Keyword(s):

Film Thickness ◽

Mathematical Models ◽

Piston Ring ◽

Published Data ◽

Predictive Tool ◽

Frictional Losses ◽

Fundamental Understanding ◽

Minimum Film Thickness ◽

Piston Ring Pack ◽

Ring Pack

Fundamental understanding of piston ring-pack lubrication is essential in reducing engine friction. This is because a substantial portion of engine frictional losses come from piston-ring assembly. Hence, this study investigates the tribological impact of different piston ring profiles towards engine in-cylinder friction. Mathematical models are derived from Reynolds equation by using Reynolds’ boundary conditions to generate the contact pressure distribution along the complete piston ring-pack/liner conjunction. The predicted minimum film thickness is then used to predict the friction generated between the piston ring-pack and the engine cylinder liner. The engine in-cylinder friction is predicted using Greenwood and Williamson’s rough surface contact model. The model considers both the boundary friction and the viscous friction components. These mathematical models are integrated to simulate the total engine in-cylinder friction originating from the studied piston ring-pack for a complete engine cycle. The predicted minimum film thickness and frictional properties from the current models are shown to correlate reasonably with the published data. Hence, the proposed mathematical approach prepares a simplistic platform in predicting frictional losses of piston ring-pack/liner conjunction, allowing for an improved fundamental understanding of the parasitic losses in an internal combustion engine.

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