Heat transfer model for small-scale spark-ignition engines

Wu, Yuh‐Yih; Chen, Bo–Chiuan; Hsieh, Feng-Chi; Ke, Cheng-Ting

doi:10.1016/j.ijheatmasstransfer.2008.10.015

Cited by 20 publications

(11 citation statements)

References 13 publications

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“…Over the last 50 years, many authors have proposed several correlations to compute h. One family of correlations is based on a Stanton number correlation [12,13], but the large majority of available models are based on a Nusselt number correlation [14][15][16][17]:…”

Section: Heat Transfer Modelmentioning

confidence: 99%

Convective Heat Transfer in a Pneumatic Hybrid Engine

Brejaud

Higelin

Charlet

et al. 2011

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

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Résumé -Échange de chaleur convectif dans un moteur hybride pneumatique -Plusieurs études ont déjà montré que le concept d'hybride pneumatique est une alternative techniquement et économiquement viable à l'hybridation électrique. Malgré l'absence de combustion lors d'un fonctionnement en mode entraîné ou pneumatique, les échanges de chaleurs convectifs restent un facteur de premier ordre sur un bilan énergétique. Il faut donc disposer d'un modèle précis d'échange de chaleur instantané afin de prévoir la pression instantanée dans un cylindre du moteur. Cette étude montre que, à cause de l'extinction du mouvement de tumble à l'approche du point mort haut, la forme originale du modèle de Woschni n'est pas adaptée, pour un moteur opérant en mode pneumatique entraîné, à décrire la forme mesurée des échanges de chaleurs instantanés en fonction de l'angle vilebrequin. Les auteurs proposent une modification du modèle de Woschni décrivant plus fidèlement les échanges de chaleurs instantanés lors des courses de compression et de détente, applicable pour les modes pneumatique et entraîné avec coupure d'injection. En premier lieu, le nouveau modèle à paramètres constants est identifié à partir de mesures expérimentales effectuées en mode entraîné sous diverses conditions opératoires. Le mode suralimentation pneumatique sans combustion (allumage non déclenché) est alors étudié, en utilisant des valeurs de paramètres identiques à celles utilisées en mode entraîné. Cette étude montre que le modèle modifié reste pleinement applicable au mode suralimenté, et ceci malgré une certaine modification de la structure aérodynamique interne du cylindre créée par l'ouverture de la soupape de charge sous un haut rapport de pression. Abstract -Convective Heat Transfer in a Pneumatic Hybrid Engine -Several previous studies have proven that pneumatic hybridization of an internal combustion engine is a technically viable and cost-efficient alternative to electric hybridization. Because the heat transfer process remains a first order factor while the engine operates in a motored

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Section: Heat Transfer Modelmentioning

confidence: 99%

Convective Heat Transfer in a Pneumatic Hybrid Engine

Brejaud

Higelin

Charlet

et al. 2011

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

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“…These approaches implicitly assume errors that can be acceptable for heat balances but can involve uncertainties in simulation cycles or temperature distribution analyses. It should be noticed that some authors, after having identified one correlation for one small-scale air-cooled engine [18], acknowledge that those correlation parameters are not valid for another small scale air-cooled engine with similar characteristics [19].…”

Section: Introductionmentioning

confidence: 99%

“…For example, in the case of water-cooled engines, this temperature is often assumed to be equal to the coolant temperature or is calculated from hypotheses that are specific for water-cooled engines [15] and normally assume constant temperature for all operating points. This approach can not be extrapolated to air-cooled engines because the temperature field in the inner surface changes with the operating conditions [19]. Very few studies concerning heat transfer in aircooled engines have been published and most of them consider two-stroke and/or sparkignition engines [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

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Methodology for the estimation of cylinder inner surface temperature in an air-cooled engine

Trujillo

Aguilar

Villanueva

et al. 2011

Applied Thermal Engineering

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A methodology for the estimation of the mean temperature of the cylinder inner surface in an air-cooled internal combustion engine is proposed. Knowledge of this temperature is necessary to determine the heat flux from the combustion chamber to the cylinder wall. Along with the heat transfer coefficient this parameter also allows almost 50% of engine heat losses to be determined. The temperature is relatively easy to determine for water-cooled engines but this is not in the case for air-cooled engines. The methodology described here combines numerical and experimental procedures. Simulations were based on FEM models and experiments were based on the use of thermocouples and infrared thermography. The methodology avoids the use of data or correlations developed for other engines, providing more reliable results than extrapolating models from one engine to another. It also prevents from taking measurements from inside the combustion chamber, reducing invasion and experiments complexity. The proposed methodology has been successfully applied to an air-cooled four-stroke directinjection diesel engine and it allows the cylinder mean inner surface temperature and cylindercooling air heat transfer coefficient to be estimated.

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“…For this reason there exist a large number of studies which treat jointly both processes. Nevertheless, in most cases, to obtain the heat release, wall temperature or heat transfer rate were imposed [3,4,7,8], or wall temperature was obtained as a function of engine operation parameters [9,10]. Other works [11,12] are mainly focussed on the piston and do not analyse other engine parts.…”

Section: Introductionmentioning

confidence: 99%