Contributions to Engine Friction During Cold, Low Speed Running and the Dependence on Oil Viscosity

Shayler, P. J.; Leong, D. K. W.; Murphy, Michael C.

doi:10.4271/2005-01-1654

Cited by 50 publications

(27 citation statements)

References 7 publications

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“…Consequently, low temperatures in Diesel engines mainly influence the friction [15], whereas in [14,17] for a petrol engine both thermodynamic efficiency and friction are temperature dependent. In [18], the viscosity of the engine lubricant is identified as the largest contributor of increased friction at cold and, like [19], he extends friction modeling of the warm ICE [20], to cold conditions. It should be noted that due to the complexity of the physical mechanisms, the models are of an empirical nature.…”

Section: Internal Combustion Engine During Warm-upmentioning

confidence: 99%

Optimal Control of Engine Warmup in Hybrid Vehicles

Reeven

Hofman

Willems

et al. 2014

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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-An Internal Combustion Engine (ICE) under cold conditions experiences increased friction losses due to a high viscosity of the lubricant. With the additional control freedom present in hybrid electric vehicles, the losses during warmup can be minimized and fuel can be saved. In this paper, firstly, a control-oriented model of the ICE, describing the warmup behavior, is developed and validated on measured vehicle data. Secondly, the two-state, non-autonomous fuel optimization, for a parallel hybrid electric vehicle with stop-start functionality, is solved using optimal control theory. The principal behavior of the Lagrange multipliers is explicitly derived, including the discontinuities (jumps) that are caused by the constraints on the lubricant temperature and the energy in the battery system. The minimization of the Hamiltonian for this two-state problem is also explicitly solved, resulting in a computationally efficient algorithm. The optimal controller shows the fuel benefit, as a function of the initial temperature, for a long-haul truck simulated on the FTP-75.Résumé -Contrôle optimal d'échauffement du moteur dans les véhicules hybrides -Un moteur à combustion interne (ICE, Internal Combustion Engine) en condition froide provoque une croissance de pertes de frottement suite à la viscosité élevée du lubrifiant. Dues à la commande libre supplémentaire appliquée dans les véhicules électriques hybrides, les pertes d'échauffement peuvent être réduites au maximum tout en économisant du carburant. Dans cet article, premièrement, un modèle de contrôle de l'ICE, décrivant le comportement d'échauffement, a été développé et validé par les données mesurées sur le moteur. Deuxièmement, dans un véhicule électrique hybride parallèle avec la fonctionnalité d'arrêt-démarrage, l'optimisation du double-état, non-autonome, du carburant est résolue en appliquant la théorie du contrôle optimal. Le comportement principal des multiplicateurs de Lagrange est explicitement dérivé, y compris les discontinuités (sauts) qui sont causées par les contraintes de la température du lubrifiant et par la capacité dans le système de batterie. La minimisation de l'Hamiltonien de ce problème de doubleétat est aussi explicitement résolue, résultant en un algorithme de calcul efficace. Le régulateur optimal indique l'économie du carburant en fonction de la température initiale, pour un grand routier simulé sur le FTP-75.

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Section: Internal Combustion Engine During Warm-upmentioning

confidence: 99%

Optimal Control of Engine Warmup in Hybrid Vehicles

Reeven

Hofman

Willems

et al. 2014

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

View full text Add to dashboard Cite

show abstract

“…Figure 2. Distribution of engine friction contributions predicted using the model described in [1], at 1500 rpm, fully warm operating conditions.…”

Section: Engine Specificationsmentioning

confidence: 99%

“…A predicted breakdown of friction contributions made by the main component groups is given in Figure 2, for an engine speed of 1500 rpm and SAE 5W-30 oil at a bulk temperature of 90°C. The predictions were made using the model described in [1]. The oil pump contribution has been deleted from the ancillaries because in the current studies, the pump was independently driven by an electric motor connected to an external electrical supply.…”

Section: Engine Specificationsmentioning

confidence: 99%

“…This can entail sliding motion such as between the piston and the cylinder liner, rolling-sliding motion between cams and roller followers, and rotational motion in the journal bearings. Collectively these produce a friction mean effective pressure, FMEP, of the order of 1 bar [1]. This is a significant part of the indicated load, given brake mean effective pressures under mixed European driving conditions are typically a few bar, reducing engine efficiency and causing engine wear.…”

Section: Introductionmentioning

confidence: 99%

“…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].…”

Section: Introductionmentioning

confidence: 99%

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A Modified Oil Lubrication System with Flow Control to Reduce Crankshaft Bearing Friction in a Litre 4 Cylinder Diesel Engine

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Diesel Engine Preheating and Starting Simulation with Modelica Language

Malozemov

Bondar

Malozemov³

2018

Proceedings of the 4th International Conference on Industrial Engineering

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The article presents the results of mathematical model and software development for the simulation of diesel engine preheating and starting with the Modelica language. The model is based on the energy and mass balance method, Godunov scheme, Wiebe, and Razleytsev equations, and is a library of Modelica classes which describe the processes in engine systems and mechanisms including air and electrical starters, preheaters, and start facilities tools. The mathematical model includes the description of different boundary conditions, acausal connections, and basic and complex elements, such as a(n) electric and fuel coolant preheater, air heater in gas pipes, and compressed air starting system. The created mathematical model and software provides high speed calculation, reliability and accuracy of results, that is confirmed by comparison with experimental data. The possibility of conjugate calculation of stationary and transient multi-domain processes in various engine systems and mechanisms is ensured.

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Contributions to Engine Friction During Cold, Low Speed Running and the Dependence on Oil Viscosity

Cited by 50 publications

References 7 publications

Optimal Control of Engine Warmup in Hybrid Vehicles

Optimal Control of Engine Warmup in Hybrid Vehicles

A Modified Oil Lubrication System with Flow Control to Reduce Crankshaft Bearing Friction in a Litre 4 Cylinder Diesel Engine

Diesel Engine Preheating and Starting Simulation with Modelica Language

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