An Analysis of Ring Temperature, Oil Film Temperature, Oil Film Thickness and Heat Transfer on a Piston Ring of an IC Engine in Consideration of Ring Movement in a Cycle

Author(s):  
Takashi Ishijima ◽  
Akiko Shimada ◽  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Masaaki Takiguchi

An unsteady and two-dimensional thermohydrodynamic lubrication model in consideration of the ring movement and the heat flow from ring groove to piston ring was developed. The piston ring temperature in an internal combustion engine was analyzed by using the unsteady and two-dimensional form heat-conduction equation in consideration of axial movement of ring and heat flow from ring groove to ring during a cycle. The oil film temperature, oil film thickness and heat transfer between ring and liner surfaces were analyzed by using the calculated ring temperature taking into consideration cycle variation. The results are as follows. The heat flow rate around ring changes greatly with the ring movement and the ring sliding face temperature changes about 6 °C in a cycle. Then, the cycle mean temperature of ring sliding face becomes lower than the ring sliding face temperature calculated by the ring groove and liner surface temperatures under 2800 rpm and full load conditions. Therefore, the oil film viscosity is higher than that of the conventional viscosity model in which the viscosity was based on a constant ring sliding face temperature in a cycle. The oil film thickness predicted by the present method is thicker than that calculated by our previous method.

Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Masaaki Takiguchi

Abstract This paper describes that an analysis of oil film thickness on a piston ring of diesel engine. The oil film thickness has been performed by using Reynolds equation and unsteady, two-dimensional (2-D) energy equation with a heat generated from viscous dissipation. The temperature distribution in the oil film is calculated by using the energy equation and the mean oil film temperature is computed. Then the viscosity of oil film is estimated by using the mean oil film temperature. The effect of oil film temperature on the oil film thickness of a piston ring was examined. This model has been verified with published experimental results. Moreover, the heat flow at ring and liner surfaces was examined. As a result, the oil film thickness could be calculated by using the viscosity estimated from the mean oil film temperature and the calculated value is agreement with the measured values.


Author(s):  
Takashi Ishijima ◽  
Akiko Shimada ◽  
Shinichiro Kodaira ◽  
Hiroshi Sakamoto ◽  
Yasuo Harigaya ◽  
...  

For the clarification of the lubrication and thermal problems between ring and liner of internal combustion engines, an unsteady thermohydrodynamic lubrication model considering the ring temperature and the ring movement in the piston ring groove was developed. Then using the method of thermohydrodynamic lubrication, the effect of the profile of top ring sliding face on the oil film thickness and friction losses was analyzed. The ring is width of 3mm and thickness of 4.5mm. Profiles in sliding face of the ring used are two types. Ring 1 has a flat in the middle and a roundness in the corner, and Ring 2 has a barrel face. The ring temperature on the sliding surface shows the characteristic temperature distribution, and the temperature difference between ring lower face and middle of ring has about 19 °C. The oil film thickness changed in a cycle increases with increase of barrel height. The friction mean effective pressure FMEP decreases with the increase of barrel height both Ring 1 and Ring 2. FMEP of Ring 2 is more effective than that of Ring 1.


2004 ◽  
Vol 128 (3) ◽  
pp. 685-693 ◽  
Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Fujio Toda ◽  
Masaaki Takiguchi

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.


Author(s):  
K Liu ◽  
Y. B. Xie ◽  
C. L. Gui

Based on the two-dimensional average flow model and asperity contact model, a theoretical model for the non-axisymmetrical analysis of piston ring lubrication has been suggested in this paper. The two-dimensional distribution of oil-film thickness between the piston rings and cylinder wall is obtained. Results show that the oil-film thickness along the circumference is non-uniform. Starvation is also considered in the model. The effect of secondary motion of piston assemblies on the lubrication property of the piston ring pack has also been studied.


Author(s):  
Yasuo Harigaya ◽  
Michiyoshi Suzuki ◽  
Fujio Toda ◽  
Masaaki Takiguchi

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.


2016 ◽  
Vol 55 (2) ◽  
pp. 269 ◽  
Author(s):  
Stefan Wigger ◽  
Hans-Jürgen Füßer ◽  
Daniel Fuhrmann ◽  
Christof Schulz ◽  
Sebastian A. Kaiser

2003 ◽  
Vol 125 (2) ◽  
pp. 596-603 ◽  
Author(s):  
Y. Harigaya ◽  
M. Suzuki ◽  
M. Takiguchi

This paper describes an analysis of oil film thickness on a piston ring of a diesel engine. The analysis of the oil film thickness has been performed by using Reynolds equation and unsteady, two-dimensional energy equation with heat generated from viscous dissipation. The mean oil film temperature was determined from the calculation of the temperature distribution in the oil field which was calculated using the energy equation. The oil film viscosity was then estimated using the mean oil film temperature. The effect of oil film temperature on the oil film thickness of a piston ring was examined. This model has been verified with published experimental results. Moreover, the heat flow at ring and liner surfaces was examined. Results show that the oil film thickness could be calculated using the viscosity estimated from the mean oil film temperature. The calculated values generally agree with the measured values. For higher engine speed conditions, the maximum values of the calculated oil film thickness are larger than the measured values.


Author(s):  
Yibin Guo ◽  
Wanyou Li ◽  
Dequan Zou ◽  
Xiqun Lu ◽  
Tao He

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.


1983 ◽  
Vol 26 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Shoichi Furuhama ◽  
Chikashi Asahi ◽  
Masaru Hiruma
Keyword(s):  

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