The Effect of Micro-Grooves on Hydrodynamic Lubrication Characteristics of a Piston Ring and a Cylinder Liner

2011 ◽  
Author(s):  
S. I. Son ◽  
K. W. Kim
Keyword(s):  
Pressure Distribution ◽  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Friction Loss ◽  
Universal Equation ◽  
Cavitation Region ◽  
Length Width ◽  
Lubrication Characteristics ◽  
Engine Cycle

In this study, the effect of micro-grooves on hydrodynamic fabrication characteristics between a piston ring and a micro-grooved cylinder liner is analyzed numerically. Elrod’s universal equation satisfying JFO theory is adopted to predict the cavitation region properly and calculate the pressure distribution between a piston ring and a micro-grooved cylinder liner. The analysis is carried out by varying the shape, depth, length, width and location of micro-grooves during the full engine cycle. The results show that micro-grooves can make friction loss decrease in comparison with a non-textured cylinder liner.

Numerical Simulation on the Lubrication Performance of Surface Textured Piston Rings

2011 ◽  
Vol 199-200 ◽  
pp. 734-738 ◽  
Author(s):  
Qiu Ying Chang ◽  
Xian Liang Zheng ◽  
Qing Liu
Keyword(s):  
Numerical Simulation ◽  
Film Thickness ◽  
Friction Force ◽  
Friction And Wear ◽  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Area Density ◽  
Oil Film ◽  
Lubrication Performance

Surface texturing has been successfully employed in some tribological applications in order to diminish friction and wear. This technology may be used in a piston ring to decrease the friction and wear of the contact between a piston ring and cylinder liner. A numerical simulation of lubrication between a surface textured piston ring and cylinder liner based on the hydrodynamic lubrication theory was conducted. The influence of surface texture parameters on piston ring lubrication performance was obtained by solving the mathematical equations with a multi-grid method. The results show that under the micro-dimple area density of 5%-40% the minimum oil film thickness increases and the dimensionless friction force decreases with the increasing of it. Under the dimple area density of 40%-60%, the minimum oil film thickness and the dimensionless friction force change slightly. Under various dimple area densities the optimum dimple depth at the given working condition in this paper is about 5µm.

On the lubrication characteristics of piston ring under different engine operation conditions

2019 ◽  
Vol 72 (1) ◽  
pp. 101-108
Author(s):  
Jun Sun ◽  
Xiao Zhang ◽  
Jianxiong Zhu ◽  
Yaming Gao ◽  
Hu Wang ◽  
...  
Keyword(s):  
Piston Ring ◽  
Cylinder Liner ◽  
Operating Conditions ◽  
Lubricating Oil ◽  
Cylinder Wall ◽  
Engine Operation ◽  
Operating Condition ◽  
Content Type ◽  
Lubrication Characteristics ◽  
Stroke Engine

Purpose Currently, lubrication analysis of piston ring is generally done under engine rated operating condition. However, the engine (such as the vehicle engine) does not always operate in rated operating condition, and its operating condition changes frequently in actual use. In addition, the lubrication status of piston ring is generally assumed as the flooded lubrication or a certain form of poor lubrication in most of the lubrication analysis. Design/methodology/approach In this paper, based on the equations about the flow rate of lubricating oil and the variation of control volume, the flow model of lubricating oil in the piston ring-cylinder liner conjunction is established. The lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done, in which the lubricating oil at the inlet of piston ring is considered as the lubricating oil attached on the relevant location of cylinder wall after the piston ring moves over at the previous stroke. Findings There is remarkable difference for the lubrication characteristics of the piston ring under different engine operating conditions. The worst lubrication status of piston ring may not take place under engine rated operating condition. Originality/value In this paper, based on the measured engine cylinder pressure, the lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done in which the lubricating oil supply condition at the inlet of piston ring is considered. The results of this paper are helpful for the design and research of engine piston ring-cylinder liner conjunction.

Theoretical Modeling and Simulation of Piston Ring Assembly of an IC Engine

2004 ◽  
Author(s):  
Kishore Mistry ◽  
D. V. Bhatt ◽  
N. R. Sheth
Keyword(s):  
Friction Force ◽  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Lubrication System ◽  
Ic Engine ◽  
Frictional Loss ◽  
Frictional Losses ◽  
Ring Assembly ◽  
Ring Geometry

Frictional losses in an IC engine are observed between 17–19% of total induced horsepower. 35–45% frictional losses observed due to piston ring assembly only from the above-referred total frictional loss. Lubrication system is for reducing the frictional losses and under the total hydrodynamic lubrication system, if made it feasible, above referred losses can be reduced considerably. Wear normally observed at TDC and BDC during the power stroke. Experimental set-up is prepared by using used piston-cylinder assembly of an engine. Experiment methodology is adopted based on certain assumption and simulated the entire system with an extra drive system by an electric motor with a provision of various speed availability. Various pockets on cylinder liner of 2mm diameter are located on the periphery of cylinder liner to offer lubrication to the system. Care was taken to control the rate of lubrication flow with the help of control knob. Seven different profiles on piston ring were generated and measured. Friction force is calculated by power consumption measurement under different dynamic condition with a variation of 5-speed, 3- lubricants and different 8- types of piston ring geometry are experimented under different combination and results are tabulated. Graphs are plotted for friction force v/s speed for different lubricants and piston ring profiles. Effect of lubricants (SAE30, 15W40& 2T) and ring geometry are compared.

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

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.

scholarly journals Investigation of different piston ring curvatures on lubricant transport along cylinder liner in large two-stroke marine diesel engines

2017 ◽  
Vol 232 (1) ◽  
pp. 85-93 ◽  
Author(s):  
H Overgaard ◽  
P Klit ◽  
A Vølund
Keyword(s):  
Diesel Engine ◽  
Piston Ring ◽  
Reynolds Equation ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Marine Diesel Engine ◽  
Cyclic Variation ◽  
Ring Shape ◽  
Marine Diesel ◽  
The Finite Difference Method

A theoretical investigation of the hydrodynamic lubrication of the top compression piston ring in a large two-stroke marine diesel engine is presented. The groove mounted piston ring is driven by the reciprocal motion of the piston. The ring shape follows a circular geometry and the effect of changes in radii is analysed. A numerical model based on the finite difference method in 1D has been developed for solving Reynolds equation in combination with the load equilibrium equation together with flow continuity between the piston ring surface and liner for analysis of the lubricant transport. The cyclic variation throughout one stroke is presented for the minimum film thicknesses at different interesting locations of the piston ring surface together with the friction and the pressure distribution history. The aforementioned parameters have been investigated numerically. The numerical results are presented and discussed.

Transient Thermal Hydrodynamic Lubrication Analysis of Textured Piston Ring/Cylinder Liner

2018 ◽  
Vol 279 ◽  
pp. 172-178
Author(s):  
Sheng Gang Guo ◽  
Bin Wang ◽  
Qiu Ying Chang
Keyword(s):  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Maximum Temperature ◽  
Temperature Elevation ◽  
Factors Affecting ◽  
Oil Film ◽  
Factors Influencing ◽  
Main Factors ◽  
Transient Thermal

On the basis of transient thermal hydrodynamic lubrication (TTHL) simulation and isothermal hydrodynamic lubrication (IHL) simulation of textured piston ring/cylinder liner, main factors influencing oil film temperature, distribution of the maximum temperature, and comparison between two models were discussed. The results show that texturing improves hydrodynamic lubrication situations, and velocity of piston ring and applied load are two important factors affecting oil film temperature. Apart from that, sever temperature elevation is located at the export of oil film and textured areas. Although change trends of the maximum of pressure and the minimum of oil film thickness are basically the same, the values of them are different. Temperature is a necessary element for analyzing the lubricant situations of piston ring/cylinder liner.

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