Coupled Model of Partially Flooded Lubrication and Oil Vaporization in an Internal Combustion Engine

Author(s):  
Boon-Keat Chui ◽  
Harold J. Schock ◽  
Andrew M. Fedewa ◽  
Dan E. Richardson ◽  
Terry Shaw

The cylinder-kit assembly of an internal combustion engine experiences severe conditions during engine operation. The top compression ring, in particular, undergoes extreme stress directly from cylinder gas pressure, inertial and thermal loads. The top compression ring is often the most significantly affected piston ring, and one of the common resultant phenomena is high wear on the ring/bore surfaces. In many previous studies, the modeling of tribological phenomena at the top compression ring/bore region involves hydrodynamic and boundary lubrication, friction and wear. This present work accounts for an additional factor that may affect the piston ring/bore lubrication — the lubricant evaporative effect. A three-dimensional oil evaporative analysis is coupled into the calculation of mixed lubrication in a cyclic engine computation. The presence of the evaporation analysis allows the study of the temperature influence on the piston ring/bore lubrication in addition to its effect on oil viscosity. A prospective application of this model is in diesel engine analysis. Considering the broad operating range of modern diesel fuel injection systems, the injection timing can be made throughout the compression/expansion process. It is well demonstrated that certain areas of fuel injection operation can result in potential adverse consequences such as increased bore wear. A well known example is “bore wall fuel wetting.” Given concerns around the potential for wear-inducing interactions between the fuel injection plumes and the bore wall, we have explored a particular interaction: bore wear in response to an imposed local heating of the bore wall. The simulation result provides valuable insights on this interaction, in which higher bore wear is predicted around bore wall area with locally imposed wall heating.

Author(s):  
C. D. Strang ◽  
J. T. Burwell

Piston rings with radio-active wearing-surfaces were used to study the micro-welding between rings and cylinder wall during “run-in” in a small, water-cooled, internal combustion engine. The results indicated that micro-welding and the accompanying transfer of metal were present under the mildest conditions of engine operation, including motoring with the engine cylinder-head removed. The distribution of micro-welding along the ring-travel was found to correspond to the wear profile observed in engine cylinders by other workers. Such transferred material may play a part in the formation of the “glazed” layer which is said to be present on “run-in” cylinder walls and rings. The presence of transferred metal at all points along the ring-travel indicates that the piston ring was not fully supported by a hydrodynamic oil film of sufficient thickness to separate completely the surfaces of the ring and the cylinder wall.


2019 ◽  
Vol 302 ◽  
pp. 01012
Author(s):  
Marietta Markiewicz ◽  
Natalia Dluhunovych

The internal combustion engine is the powerhouse of motor vehicles. The basic fuel used for self-ignition engine powering is diesel oil. The efficiency of an internal combustion engine depends on many factors and is defined by such parameters as power output, torque, and the engine rotational speed. The engine performance parameters can be improved by modification of the manufacturer’s computer software that controls the engine operation. The study presents results of tests of a drive unit involving adjusting the fuel injection controller settings. The modifications involved increasing the fuel dose and the air charge pressure. Tests were carried out on a load bearing chassis dynamometer. The research object was a self-ignition engine with 109 KM power and Common Rail injection system. Power and torque measurements were carried out for the engine rotational speed range up to 4000 rev/min. It was found that modifications of the manufacturer’s engine computer software contribute to power and torque increase for all the rotational speeds.


Author(s):  
E.T. Plaksina ◽  
A.B. Syritsky ◽  
A.S. Komshin

The article considers the main methods of internal combustion engine diagnostics. A method based on measuring the time intervals between the phases of the working cycle of the mechanism is described. An algorithm for measuring the time intervals from the formulation of the problem to the proof of the efficiency of this method on an internal combustion engine has been determined. The installation of the angle sensor on the crankshaft of the experimental bench engine VAZ 21126 is shown. The basis for the construction of a mathematical model of the crankshaft is presented and the main factors influencing its movement are identified. A criterion has been established according to which the misfire is determined most accurately. The results obtained can be used for developing diagnostic systems for internal combustion engines, as well as engines operating in extreme conditions, for example, beyond the Arctic Circle, on ships, etc.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 395
Author(s):  
Jeongwoo Song ◽  
Han Ho Song

The exergy destruction due to the irreversibility of the combustion process has been regarded as one of the key losses of an internal combustion engine. However, there has been little discussion on the direct relationship between the exergy destruction and the work output potential of an engine. In this study, an analytical approach is applied to discuss the relationship between the exergy destruction and efficiency by assuming a simple thermodynamic system simulating an internal combustion engine operation. In this simplified configuration, the exergy destruction during the combustion process is mainly affected by the temperature, which supports well-known facts in the literature. However, regardless of this exergy destruction, the work potential in this simple engine architecture is mainly affected by the pressure during the combustion process. In other words, if these pressure conditions are the same, increasing the system temperature to reduce the exergy destruction does not lead to an increase in the expansion work; rather, it only results in an increase in the remaining exergy after expansion. In a typical internal combustion engine, temperatures before combustion timing must be increased to reduce the exergy destruction, but increasing pressure before combustion timing is a key strategy to increase efficiency.


2019 ◽  
Vol 71 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Venkateswara Babu P. ◽  
Ismail Syed ◽  
Satish Ben Beera

Purpose In an internal combustion engine, piston ring-cylinder liner tribo pair is one among the most critical rubbing pairs. Most of the energy produced by an internal combustion engine is dissipated as frictional losses of which major portion is contributed by the piston ring-cylinder liner tribo pair. Hence, proper design of tribological parameters of piston ring-cylinder liner pair is essential and can effectively reduce the friction and wear, thereby improving the tribological performance of the engine. This paper aims to use surface texturing, an effective and feasible method, to improve the tribological performance of piston ring-cylinder liner tribo pair. Design/methodology/approach In this paper, influence of positive texturing (protruding) on friction reduction and wear resistance of piston ring surfaces was studied. The square-shaped positive textures were fabricated on piston ring surface by chemical etching method, and the experiments were conducted with textured piston ring surfaces against un-textured cylinder liner surface on pin-on-disc apparatus by continuous supply of lubricant at the inlet of contact zone. The parameters varied in this study are area density and normal load at a constant sliding speed. A comparison was made between the tribological properties of textured and un-textured piston ring surfaces. Findings From the experimental results, the tribological performance of the textured piston ring-cylinder liner tribo pair was significantly improved over a un-textured tribo pair. A maximum friction reduction of 67.6 per cent and wear resistance of 81.6 per cent were observed with textured ring surfaces as compared to un-textured ring surfaces. Originality/value This experimental study is helpful for better understanding of the potency of positive texturing on friction reduction and wear resistance of piston ring-cylinder liner tribo pair under lubricated sliding conditions.


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