An Analysis of Oil Film Temperature, Oil Film Thickness and Heat Transfer on a Piston Ring of Internal Combustion Engine: The Effect of Local Lubricant Viscosity

2004 ◽  
Author(s):  
Akiko Shimada ◽  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Masaaki Takiguchi
Keyword(s):  
Heat Transfer ◽  
Film Thickness ◽  
Internal Combustion Engine ◽  
Piston Ring ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Oil Film ◽  
Lubricant Viscosity

The Simple Model of the Oil Film Thickness between Piston Ring and Cylinder

2010 ◽  
Vol 97-101 ◽  
pp. 1239-1242
Author(s):  
De Liang Liu ◽  
Hui Biao Lu ◽  
C.G. Sun
Keyword(s):  
Film Thickness ◽  
Internal Combustion Engine ◽  
Piston Ring ◽  
Reynolds Equation ◽  
Combustion Engine ◽  
Friction Pair ◽  
Internal Combustion ◽  
Theoretical Research ◽  
Lubricating Oil ◽  
Oil Film

Piston ring-cylinder is one of the most important friction pair of internal combustion engine，the lubricating state between them has decided internal combustion engine lubrication quality. So the theoretical research to the lubricating characteristics of the piston-ring group, especially the calculation of the lubricating oil film thickness is very important. The oil film thickness between piston-ring and cylinder is studied by calculation method. The calculation program is developed with average Reynolds equation taken the surface topography, viscosity-temperature effect, viscosity-pressure effect, extrusion effect and other factors into account. The position of oil outlet point is preinstalled, the full lubrication is assumed, and the Reynolds equation is solved by full pivot element gausses elimination approach, so the iterative course and calculation workload are reduced, and a great lot of the calculating time is saved, the oil film thickness of full period can be more accurately predicted by the ordinary PC within 30 minutes, which can supply quick effective evidence for next calculation and analysis.

Analysis of Oil Film Thickness and Heat Transfer on a Piston Ring of a Diesel Engine: Effect of Lubricant Viscosity

2004 ◽  
Vol 128 (3) ◽  
pp. 685-693 ◽  
Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Fujio Toda ◽  
Masaaki Takiguchi
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Shear Rate ◽  
Film Thickness ◽  
Piston Ring ◽  
Unsteady State ◽  
Oil Film ◽  
The Mean ◽  
Lubricant Viscosity ◽  
Load Conditions

The effect of lubricant viscosity on the temperature and thickness of oil film on a piston ring in a diesel engine was analyzed by using unsteady state thermohydrodynamic lubrication analysis, i.e., Reynolds equation and an unsteady state two-dimensional energy equation with heat generated from viscous dissipation. The oil film viscosity was then estimated by using the mean oil film temperature and the shear rate for multigrade oils. Since the viscosity for multigrade oils is affected by both the oil film temperature and shear rate, the viscosity becomes lower as the shear rate between the ring and liner becomes higher. Under low load conditions, the viscosity decreases due to temperature rise and shear rate, while under higher load conditions, the decrease in viscosity, is attributed only to the shear rate. The oil film thickness between the ring and liner decreases with a decrease of the oil viscosity. The oil film thickness calculated by using the viscosity estimated by both the shear rate and the oil film temperature gave the smallest values. For multigrade oils, the viscosity estimation method using both the mean oil film temperature and shear rate is the most suitable one to predict the oil film thickness. Moreover, the heat transfer at ring and liner surfaces was examined.

Analysis of Oil Film Thickness and Heat Transfer on a Piston Ring of a Diesel Engine: Effect of Lubricant Viscosity

2002 ◽  
Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Fujio Toda ◽  
Masaaki Takiguchi
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Shear Rate ◽  
Film Thickness ◽  
Piston Ring ◽  
Unsteady State ◽  
Oil Viscosity ◽  
Oil Film ◽  
Higher Temperature ◽  
Lubricant Viscosity

The effect of lubricant viscosity on the temperature and thickness in oil film on a piston ring in a diesel engine was analyzed by using unsteady state thermohydrodynamic lubrication analysis, that is Reynolds equation and an unsteady state two-dimensional (2-D) energy equation with heat generated from viscous dissipation. The oil film viscosity was then estimated by using the mean oil film temperature and the shear rate for multi grade oils. The shear rate between the ring and liner becomes higher, so that the viscosity for the multi grade oil is affected by the oil film temperature and shear rate, and the viscosity becomes lower. Under low temperature condition, the viscosity becomes lower due to viscous heating and shear rate and under higher temperature condition, the viscosity affected by the shear rate becomes lower. The oil film thickness between the ring and liner decreases with decrease of the oil viscosity, and it is the thinnest that the oil film thickness is calculated by using the viscosity estimated by both the shear rate and the oil film temperature. Moreover, the heat transfer at ring and liner surfaces was examined.

Piston Ring Load Carrying Capacity: Influence of Cross-Hatching Parameters

2012 ◽  
Author(s):  
H. Bouassida ◽  
N. Biboulet ◽  
P. Sainsot ◽  
A. A. Lubrecht
Keyword(s):  
Film Thickness ◽  
Internal Combustion Engine ◽  
Carrying Capacity ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The Cross

Energy and environment are of major concern in internal combustion engine component design. The piston ring-cylinder liner (PRCL) contact plays an essential part in design and is highlighted in this study. In fact, the rings ensure the sealing property, reducing the environmental impact by avoiding lubricant contamination (blow-by) and lubricant consumption. Unfortunately, when sealing, the rings generate between 11 to 24% of the friction losses in an internal combustion engine [1], thus reducing the energy efficiency of the engine. The cylinder liner surface features a special micro-geometry, a classical one is the cross-hatching pattern, obtained by honing. This texturing acts as a micro-bearing, oil reservoir and debris trap. Understanding the influence of texture parameters as groove depth and width or angle, will allow tribological improvements of the PRCL contact. The 2D transient Reynolds equation has to be solved for this kind of surface. The statistical method using the Patir and Cheng [2] flow factors is widely used. This approach lumps the different components of the surface (grooves and plateaux) and does not consider the roughness directionality. Methods decoupling both components, like the homogenization method [3] are also used. Another alternative is to use a deterministic model on measured surfaces, but this is a “hugely” expensive approach. Multigrid methods [4] are used to drastically reduce the calculational cost. The aim of the current study is to facilitate the understanding of measured surface calculations. Hence, analytical surfaces are used. They allow a flexible handling of the cross-hatching parameters. The plateaux are perfectly smooth and the grooves are sinusoidally shaped. The top ring is modelled using a parabolic profile. Periodic boundary conditions are used in the orthoradial direction and zero pressure conditions (Dirichlet) in the axial direction. To investigate the effect of different parameters, various imposed film thicknesses are applied and the mean load carrying capacity (LCC) over time is calculated. When representing the LCC corresponding to each parameter compared to the smooth LCC, as a function of the logarithm of the minimum film thickness, the curves are quite linear for small values of the film thickness and then for larger values they converge to 1.

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