Crank angle resolved floating-liner friction measurements on microstructured cylinder liner surfaces

Author(s):  
Henning Pasligh ◽  
K. Oehlert ◽  
F. Dinkelacker ◽  
H. Ulmer
1999 ◽  
Vol 123 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Ozgen Akalin ◽  
Golam M. Newaz

An axi-symmetric, hydrodynamic, mixed lubrication model has been developed using the averaged Reynolds equation and asperity contact approach in order to simulate frictional performance of piston ring and cylinder liner contact. The friction force between piston ring and cylinder bore is predicted considering rupture location, surface flow factors, surface roughness and metal-to-metal contact loading. A fully flooded inlet boundary condition and Reynolds boundary conditions for cavitation outlet zone are assumed. Reynolds boundary conditions have been modified for non-cavitation zones. The pressure distribution along the ring thickness and the lubricant film thickness are determined for each crank angle degree. Predicted friction force is presented for the first compression ring of a typical diesel engine as a function of crank angle position.


Author(s):  
M. E. Leustek ◽  
C. Sethu ◽  
S. Bohac ◽  
Z. Filipi ◽  
D. Assanis

The instantaneous IMEP method is used to measure crank-angle resolved in-cylinder friction force in a series production spark ignition engine as a function of design parameters and operating conditions. An improved telemetry system, which continues to provide data after 50+ hours of operation at speeds as high as 2000 rpm, is presented. Primary sources of error associated with the technique will be presented. These include intra-cycle engine speed fluctuations, the effect of thermal shock on pressure transducers, the effect of connecting rod force calibration and measurement error. The instantaneous IMEP method is used to measure crank-angle resolved in-cylinder engine friction as functions of engine speed and coolant (oil-film) temperature. Both crank-angle resolved and cycle-integrated results are compared.


2019 ◽  
Vol 177 (2) ◽  
pp. 55-59
Author(s):  
Kohei NAKASHIMA ◽  
Yosuke UCHIYAMA

Apparatus was developed to measure piston assembly friction with a floating cylinder liner against crank angle, using components of an eco-mileage vehicle engine as much as possible. This apparatus was then used to investigate the effect of different sets of piston rings on piston assembly friction in an eco-mileage vehicle engine. Results indicated that, compared to the piston with all three rings (a top ring, a second ring and an oil ring), the piston with two rings (a top ring and an oil ring) reduced piston assembly friction at all engine temperatures and engine speeds. Another configuration of two rings, with the top ring and the second ring, but without the oil ring, reduced friction at a lower engine temperature and speed, but was almost the same as the three-ring set at a higher engine temperature and speed. Finally, a one-ring set, with only the top ring, further reduced friction, except at a higher temperature and speed, where friction was greater than the two-ring set without the second ring.


2013 ◽  
Vol 871 ◽  
pp. 27-31
Author(s):  
Shi Feng Zhang ◽  
Shu Hua Cao ◽  
Jiu Jun Xu

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.


2016 ◽  
Author(s):  
Valentin Soloiu ◽  
Jose Moncada ◽  
Aliyah Knowles ◽  
Tyler Naes ◽  
Emerald Simons ◽  
...  

The performance of an indirect injection engine fueled with a biodiesel blend was investigated at 2400 rpm and 6 bar IMEP. The single cylinder experimental engine was run using C50 and compared to a ULSD#2 baseline. Brassica carinata oilseed was studied as it can potentially provide improvements for existing fuel infrastructures. Cylinder pressure data for C50 showcased a lower heat release and slightly higher injection pressure due to higher SMD. Brake specific fuel consumption was 6% higher for C50 given the characteristic LHV of biodiesel. Vibrations and sound measurements were analyzed in the frequency and crank angle domain through the Brüel & Kjær PULSE software platform. Sound pressure correlations were determined according to the piston normal force on the cylinder liner, intake and exhaust valve timing, and operating speed. For both fuels, vibrations parallel to the cylinder axis reached 1.6–2.6 m/s2 in the 40–120 Hz frequency range; noise reached 80–87 dB at frequencies of 1–4 kHz. C50 produced 0.4 g/kWh fewer NOx emissions which correlate to a lower maximum bulk gas temperature and richer air-fuel ratio. The average ringing intensity was 0.05 MW/m2 for both fuels due to a comparable pressure rise rate. When the engine was run with C50, the reference mechanical efficiency of 53% was effectively maintained. This offers validation for further implementation of blended biodiesel fuel in IDI engines.


Author(s):  
Hans-Joachim Weimar ◽  
Ulrich Spicher

A new measuring technique has been developed in order to determine the oilfilm thickness between piston ring and cylinder liner in a combustion engine by use of laser-induced fluorescence (LIF) technique. In clear contrast to further investigations, where optical probes have been mounted at a fix position in the cylinder liner allowing single measurements at defined times of the piston stroke, only, the optical probes used in the presented work are mounted in the piston and the piston ring. Fiber optics, led via a grasshopper-link, carry the exciting laser radiation (λ = 488 nm) to the probes and backwards the fluorescence radiation (λ ∼ 540 nm) to a photomultiplier. Thus, the developed measuring system allows a continous, crank-angle resolved measuring of the oilfilm thickness. As the LIF-technique is a relative measuring technique, calibration work, especially in the combustion engine, had to be done. Using eddy current sensors at a fix position in the cylinder liner the oilfilm in a single point could be determined. Grooves of defined depth in the cylinder liner provided the fluorescence signal amplification in each stroke so that adverse influences of oil pollution or temperature could be eliminated. A method has been developed to eliminate transmission influences contributed to the grasshopper link system. The measuring technique adapted to a single-cylinder SI engine has been tested under motored and fired conditions. Parameters under motored conditions were engine speed, oil- and coolant-temperature and throttle position. Experiments under fired conditions (part load) have been done varying oil and coolant temperature. Correlations between oilfilm thickness and HC-emissions under motored conditions have been found. Incylinder pressure, oil-temperature and engine speed are the most influencing parameters.


Author(s):  
Mikhail A. Ejakov

Abstract The ring-pack lubrication is a complicated physical process involving multiple physical phenomena. This paper presents an attempt to model the ring-pack lubrication in three-dimensional space, considering the ring-bore structure interaction, bore distortion, ring-twist, piston secondary motion, non-Newtonian lubricant behavior, and ring/bore asperity contacts. The physics of the model includes the interface between the structure of the ring, oil lubricant, and the structure of the cylinder liner. The ring is modeled as a three-dimensional FEA model with the nodes along the ring circumference. The ring face orientation changes circumferentially depending on ring geometry as well as piston tilt angle and three-dimensional ring twist angle at every crank angle degree. The oil lubrication is modeled with the Reynolds equation with shear thinning and temperature dependent oil viscosity and with or without the flow factors. The cylinder liner description allows three-dimensional bore distortion and ring/liner asperity contact to be modelled. The key of the analysis is solving simultaneously at every crank angle increment a set of coupled linear and non-linear equations of ring structure, ring face lubrication, bore distortion, and asperity contact. The model predicts variations of the ring-pack lubrication in the axial and circumferential directions. Using the hydrodynamic lubrication model coupled with the asperity contact model allows calculations of the friction forces due to asperity contact (boundary and mixed lubrication) and oil film interactions (hydrodynamic and mixed lubrication). The transition from hydrodynamic lubrication to boundary lubrication through mixed lubrication is determined interactively based on ring / liner surface properties, ring loads, and lubrication properties. The new friction sub-module calculates axial and circumferential variation of both types of friction forces as well as total friction. The asperity contact induced friction forces and asperity contact pressure can further be used for ring wear calculations. The developed model has been applied to determine the performance of a production engine ring-pack. The influence of different phenomena affecting the ring-pack performance has been analyzed and compared.


Author(s):  
S. H. Mansouri ◽  
V. W. Wong

In this article, a previously developed and experimentally validated piston secondary motion model has been improved further numerically and applied to understand the detailed interactions between the piston skirt and the cylinder liner for various piston design parameters. The model considers the roughness of the surfaces and the topography of the skirt in both the axial (barrel profile) and circumferential (ovality) directions. Three modes of lubrication: hydro-dynamic, mixed, and boundary lubrication regimes have been considered and the skirt is partially flooded in most cases. Elastic deformation of the skirt is an essential part of the model. In this model, the piston dynamic behaviour and frictional and impact forces are predicted as functions of crank angle and are examined in detail. Parameters investigated include piston skirt profile, piston-to-liner clearance, surface roughness, and oil availability. The results show that some of these parameters have profound effects on the frictional and impact forces at the piston skirt/liner interface, and therefore, they have the potential to optimize the piston frictional power loss. Correlations and non-dimensional scaling laws are developed to illustrate the basic governing phenomena. These results aim to provide a set of quantitative design guidelines.


1987 ◽  
Vol 48 (C8) ◽  
pp. C8-567-C8-572
Author(s):  
M. MORIN ◽  
M. HAOURIKI ◽  
G. GUENIN

1985 ◽  
Vol 55 ◽  
Author(s):  
J-P. Hirvonen ◽  
M. Nastasi ◽  
J. R. Phillips ◽  
J. W. Mayer

ABSTRACTMultilayered samples of Ti-Pd with linearly varying compositions were irradiated by Xe ions at 600 keV. The induced microstructures were studied by using transmission electron microscopy and Rutherford backscattering. Mixing was found to be complete over the entire composition range, resulting in amorphous or amorphous plus crystalline structures except at the palladium-rich end, where a crystalline Pd-Ti solid solution was obtained. This is consistent with the high equilibrium solubility of Ti in Pd. In addition, significant coarsening of the microstructure caused by irradiation was found in this solid solution region.Friction measurements were carried out in air and water by using a polytetrafluoroethylene pin as a counterpart. In air the friction coefficient was independent of composition and microstructure after about 2000 passes. In water, however, after 600 passes the friction coefficient reached a steady-state value with a pronounced minimum over the amorphous region. This property was unchanged throughout the remaining 10000 passes.


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