Characterising Lubricating Oil Viscosity to Describe Effects on Engine Friction

Shayler, P. J.; Allen, Andrew J.; Leong, D. K. W.; Pegg, Ian; Brown, Alisdair J.; Dumenil, J-C.

doi:10.4271/2007-01-1984

Cited by 23 publications

(7 citation statements)

References 3 publications

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“…Considering the case when biodiesel oxidizes within the lubricating oil system, it is well known that increases in the engine oil viscosity can have a substantial impact on the engine wear and vehicle fuel consumption. Shayler et al [62] demonstrated that engine oil viscometrics have a direct effect on the engine friction although the impact on the fuel usage is not presented. Building on this study, Bannister et al [63] quantified the impact that different oil viscometric properties had on the fuel consumption of a modern Euro III-compliant diesel engine.…”

Section: Viscosity and Lubricity Effects On The Lubrication Systemmentioning

confidence: 99%

“…There are relatively few data available on the impact of biodiesel oxidation on the emissions from diesel engines. Oxidation of biodiesel diluted within the crankcase oil can lead to an increase in the oil viscosity, resulting in an increase in the fuel consumption and, hence, an increase in the engine carbon dioxide (CO 2 ) emissions [62,63]. In addition to the impact that oxidation has on the engine operation from within the lubricating system, there is also the issue of oxidation of the fuel while in storage or within the vehicle fuel system.…”

Section: Effect On the Emissionsmentioning

confidence: 99%

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Oxidative Stability of Biodiesel Fuel

Bannister

Chuck

Bounds

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part D:

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Biodiesel, the fatty acid alkyl esters derived from vegetable oils, animal fats, or waste cooking oils, is an alternative to diesel fuel. One of the major technical issues with the use of biodiesel is its susceptibility to oxidation. Oxidation of biodiesel is a complex process which involves a number of mechanisms producing an array of chemical components such as aldehydes, acids, ketones, and oligomeric compounds. These components in turn increase the viscosity and deposits in the fuel beyond acceptable levels. A variety of factors affect the level of these decomposition products as well as the rate of formation and decay. These factors include the temperature, presence of light, catalytic metals in the fuel system, sump oil, or storage containers, type of biodiesel, fatty acid profile, blend level, other contaminants, and presence of antioxidants. This paper examines the relevant factors influencing the biodiesel oxidative stability, the methods used to analyse and test biodiesel oxidation, as well as the effect that oxidation has on the fuel's properties.

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Section: Viscosity and Lubricity Effects On The Lubrication Systemmentioning

confidence: 99%

Section: Effect On the Emissionsmentioning

confidence: 99%

Oxidative Stability of Biodiesel Fuel

Bannister

Chuck

Bounds

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part D:

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“…The same, SAE 5W/30 grade, lubricating oil was used for all the tests. Previous work [5,6] showed the dependence of friction on viscosity is effectively independent of SAE grade. Oil and metal temperatures were measured using K type, sheathed thermocouples at locations which include the oil main gallery and metal temperature close to the bore surface at the top, middle and bottom of the liner.…”

Section: Introductionmentioning

confidence: 98%

“…engines are a source of engine inefficiency, a cause of poor fuel economy during warm-up and an adverse influence on cold start behaviour at low ambient temperatures. The study reported here is one of a series [1][2][3][4][5][6] carried out to investigate friction in engines under motoring conditions at low temperatures and low to medium engine speeds. These are particularly relevant to cold start and warmup operating conditions.…”

Section: Introductionmentioning

confidence: 99%

Investigations of Piston Ring Pack and Skirt Contributions to Motored Engine Friction

Shayler¹,

Leong²,

Pegg³

et al. 2008

SAE Int. J. Engines

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An experimental study has been carried out to examine the influence of ring tan load and piston skirt modifications on piston assembly friction under motored engine conditions for initial temperatures of -20, 0 and 30 o C and motoring speeds within the range 400 to 2000 rev/min. The study has been carried out using the block, crankshaft and pistons of a 2.4l, 4 cylinder diesel engine with a bore and stroke of 89.9mm and 94.6mm respectively. The pistons examined are typical of current designs for light duty diesels. A range of ring pack and piston skirt modifications have been tested, in each case as part of a complete piston assembly. The first changes produced reductions in fmep of between 5% and 38%. The reduction was due to improved skirt and ring pack designs in equal measure, each giving improvements of up to 20%. From this baseline eliminating the tan load of the piston rings was projected to give a further reduction in fmep of between 10% and 20%. Increasing the piston diametric clearances by close to the difference between minimum and maximum grade clearance gave smaller improvements of between 2% and 10% relative to the baseline, and reducing skirt roughness to perfectly smooth gave a projected reduction of typically 4%, and more at low oil viscosities.

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“…Tear-down friction studies of diesel engines show that the piston assembly and interaction with the liner is the largest contributor to friction losses, followed by the crankshaft assembly and the valve train [1]. Friction reduction in power cylinders has received considerable attention [4,5] as have the development of low viscosity oils [6] and improvements in engine thermal management designed to reduce the penalty associated with higher friction during cold engine operation [7]. The higher friction is largely attributable to higher values of oil viscosity at low temperatures, and various routes to accelerate the rate of rise of bulk oil temperature after cold start-up have been explored.…”

Section: Introductionmentioning

confidence: 99%