scholarly journals Effect of cylinder de-activation on the tribological performance of compression ring conjunction

2016 ◽  
Vol 231 (8) ◽  
pp. 997-1006 ◽  
Author(s):  
SR Bewsher ◽  
R Turnbull ◽  
M Mohammadpour ◽  
R Rahmani ◽  
H Rahnejat ◽  
...  
Keyword(s):  
Power Loss ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Cylinder Liner ◽  
Combustion Efficiency ◽  
Tribological Performance ◽  
Power Losses ◽  
Cylinder Deactivation ◽  
Compression Ring ◽  
Transient Thermal

The paper presents transient thermal-mixed-hydrodynamics of piston compression ring–cylinder liner conjunction for a 4-cylinder 4-stroke gasoline engine during a part of the New European Drive Cycle (NEDC). Analyses are carried out with and without cylinder de-activation technology in order to investigate its effect upon the generated tribological conditions. In particular, the effect of cylinder deactivation upon frictional power loss is studied. The predictions show that overall power losses in the piston–ring cylinder system worsen by as much as 10% because of the increased combustion pressures and liner temperatures in the active cylinders of an engine operating under cylinder deactivation. This finding shows the down-side of this progressively employed technology, which otherwise is effective in terms of combustion efficiency with additional benefits for operation of catalytic converters. The expounded approach has not hitherto been reported in literature.

The effects of cylinder deactivation on the thermal behaviour and fuel economy of a three-cylinder direct injection spark ignition gasoline engine

2018 ◽  
Vol 233 (11) ◽  
pp. 2838-2849
Author(s):  
Michael McGhee ◽  
Ziman Wang ◽  
Alexander Bech ◽  
Paul J Shayler ◽  
Dennis Witt
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Thermal State ◽  
Direct Injection ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Spark Ignition Engine ◽  
Engine Fuel ◽  
Cylinder Deactivation ◽  
Direct Injection Spark Ignition

The changes in thermal state, emissions and fuel economy of a 1.0-L, three-cylinder direct injection spark ignition engine when a cylinder is deactivated have been explored experimentally. Cylinder deactivation improved engine fuel economy by up to 15% at light engine loads by reducing pumping work, raising indicated thermal efficiency and raising combustion efficiency. Penalties included an increase in NOx emissions and small increases in rubbing friction and gas work losses of the deactivated cylinder. The cyclic pressure variation in the deactivated cylinder falls rapidly after deactivation through blow-by and heat transfer losses. After around seven cycles, the motoring loss is ~2 J/cycle. Engine structural temperatures settle within an 8- to 13-s interval after a switch between two- and three-cylinder operation. Engine heat rejection to coolant is reduced by ~13% by deactivating a cylinder, extending coolant warm-up time to thermostat-opening by 102 s.

Influence of positive texturing on friction and wear properties of piston ring-cylinder liner tribo pair under lubricated conditions

2019 ◽  
Vol 71 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Venkateswara Babu P. ◽  
Ismail Syed ◽  
Satish Ben Beera
Keyword(s):  
Wear Resistance ◽  
Internal Combustion Engine ◽  
Friction And Wear ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Tribological Performance ◽  
Friction Reduction ◽  
Content Type

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.

Modeling Oil Evaporation From the Engine Cylinder Liner With Consideration of the Transport of Oil Species Along the Liner

2005 ◽  
Author(s):  
Liang Liu ◽  
Tian Tian ◽  
Ertan Yilmaz
Keyword(s):  
Piston Ring ◽  
Gasoline Engine ◽  
Cylinder Liner ◽  
Oil Composition ◽  
Evaporation Model ◽  
Engine Cylinder ◽  
Piston Ring Pack ◽  
Ring Pack ◽  
Model Oil ◽  
Engine Cylinder Liner

To estimate oil evaporation from an engine cylinder liner, an evaporation model has been implemented and incorporated with an existing 3-D piston ring-pack lubrication model. In this evaporation model, oil is modeled as being composed of distinct hydrocarbon species. Due to the depletion of light species and temperature variation, oil composition changes with space and time. Great emphasis was placed on the change of oil composition caused by oil transport through the ring-pack movement along the liner. The model was applied to a gasoline engine, and it was demonstrated that due to the movement of piston ring-pack, oil can be transported from the lower liner region to the upper liner region during the compression stroke, which gives a continuous supply of light species for oil evaporation.

Power Loss Investigation in an Internal Combustion Engine Piston Equipped With a Nonlinear Energy Absorber

2017 ◽  
Author(s):  
N. Dolatabadi ◽  
S. Theodossiades ◽  
S. J. Rothberg
Keyword(s):  
Power Loss ◽  
Internal Combustion Engines ◽  
Control Method ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Nonlinear Energy Sink ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Power Losses ◽  
Nonlinear Energy

The piston impacts against the cylinder liner are the most significant sources of mechanical noise in internal combustion engines. Conventionally, the severity of impacts is reduced through the modification of physical and geometrical characteristics of components in the piston assembly. These methods effectively reduce power losses at certain engine operating conditions. Moreover, the conditions leading to the reduction in power losses inversely increase the engine noise due to piston impacts. An alternative control method that is robust to fluctuations in engine operating conditions is anticipated to improve the engine’s NVH performance whilst exacerbation in power loss remains within the limits of the conventional methods. The concept of Targeted Energy Transfer (TET) through the use of Nonlinear Energy Sinks (NES) has not been applied yet in automotive powertrains. Numerical studies have shown a potential in reducing the severity of impact dynamics by controlling piston’s secondary motion. The power loss of a piston equipped with a nonlinear energy sink is investigated in this study.

scholarly journals Effect of cylinder deactivation on tribological performance of piston compression ring and connecting rod bearing

2018 ◽  
Vol 120 ◽  
pp. 243-254 ◽  
Author(s):  
N. Morris ◽  
M. Mohammadpour ◽  
R. Rahmani ◽  
P.M. Johns-Rahnejat ◽  
H. Rahnejat ◽  
...  
Keyword(s):  
Tribological Performance ◽  
Connecting Rod ◽  
Cylinder Deactivation ◽  
Compression Ring

The Tribological and Chemical Analysis of Top Ring Zone Samples of Fully Formulated Oil Taken From a Four Stroke Gasoline Engine

2005 ◽  
Author(s):  
Peter M. Lee ◽  
M. Priest ◽  
M. S. Stark ◽  
J. J. Wilkinson ◽  
J. R. Lindsay-Smith ◽  
...  
Keyword(s):  
Steady State ◽  
Chemical Analysis ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Tribological Performance ◽  
Operating Conditions ◽  
Engine Oil ◽  
Oil Degradation ◽  
Reduce Fuel Consumption ◽  
Work Samples

With increasing pressure on engine oil manufacturers to extend oil drain intervals and reduce fuel consumption, whilst changing the composition of fully formulated oils to meet the new CEC, ILSAC and OEM specifications, there is an ever increasing need to understand the effect of oil degradation on the operating conditions and tribological performance of engines [1]. This work samples oil from the rear of the top piston ring of an engine during the first 15 minutes from cold start and operating at steady state under three different loads. These samples, used 40 hour sump oil and fresh oil have been subjected to tribological tests and chemical analysis.

Influence of a DLC coating topography in the piston ring/cylinder liner tribological performance

2021 ◽  
Vol 66 ◽  
pp. 483-493
Author(s):  
Rita Ferreira ◽  
Rui Almeida ◽  
Óscar Carvalho ◽  
Luís Sobral ◽  
Sandra Carvalho ◽  
...  
Keyword(s):  
Piston Ring ◽  
Cylinder Liner ◽  
Tribological Performance ◽  
Dlc Coating
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