A thermodynamics model for the compression and expansion process during the engine’s motoring and a new method for the determination of TDC with simulation technique

Wang, Xibo; Deng, Kangyao; Fang-zheng, HE; Zhou, Zhenhua

doi:10.1016/j.applthermaleng.2006.12.012

Cited by 12 publications

(6 citation statements)

References 4 publications

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“…The correct computation of the IMEP heavily relies on the TDC adjustment carried out and largely described in Part II [2], which presented an estimated error on the mechanical TDC of +2.66 degrees. As proof for the methodology adopted, a computation of the IMEP was carried out also considering the incorrect mechanical TDC: the results showed a difference in the range from 6 to 10% between the incorrect and the correct IMEP, confirming what was reported in [46][47][48][49][50][51].…”

Section: Imep Computation and Its Covsupporting

confidence: 72%

Testing of a Modern Wankel Rotary Engine - Part III: Firing Condition Analysis

Vorraro¹,

Turner²,

Akehurst³

2022

SAE Technical Paper Series

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This work represents a further contribution to reporting experimental activities carried out on a modern Wankel rotary engine. Specifically, in this study, the firing performance of the Advanced Innovative Engineering 225CS engine is analysed. Preliminary presentations of the experimental and measurement setup and a motoring analysis were extensively covered in Part I and II of this suite of papers while the current work presents the combustion analysis of the firing indicated pressure cycles collected through the bespoke combustion analyser software developed within the project. With the Wankel rotary engine gaining popularity again due to its potential as a range extender for battery electric vehicles, the aim of this work was mainly to analyse the fuel consumption together with the overall efficiency and the emissions at different engine speeds and loads as per classic steady-state engine testing. The characteristic curves of power and torque thus derived from the experimental measurements are reported while further deductions on combustion phenomena are then drawn from an analysis of the indicated pressure cycles. Specifically, parameters such as the rate of heat release, the net heat release, the IMEP and the indicated instantaneous torque are assessed. Further considerations are drawn on the overall mechanical efficiency relying on the IMEP computed from the indicated pressure cycles and the BMEP inferred from the torqued measured experimentally under steady-state conditions. Furthermore, the effects of the combustion on the internal pressure of the Self-Pressurizing Air-Rotor-Cooling System employed are evaluated in addition to parameters such as the Coefficient of Variation of the IMEP for the evaluation of the cycleto-cycle combustion quality and engine regularity. Finally, the postprocessed data represent an update to the historical literature on Wankel rotary engines. In addition, it can be used for the development and validation of numerical models for such engines hence allowing investigation by means of simulations of the effect on efficiency and performance of the rotary engine when employing alternative fuels such as hydrogen in the future.

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Section: Imep Computation and Its Covsupporting

confidence: 72%

Testing of a Modern Wankel Rotary Engine - Part III: Firing Condition Analysis

Vorraro¹,

Turner²,

Akehurst³

2022

SAE Technical Paper Series

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“…The capacitive TDC-Sensor (AVL 428) is used to determine TDC dynamically in a motored engine. The TDC position is determined with crank angle accuracy less than 0.1° CA [23].…”

Section: Experimental Data Acquisition Systemmentioning

confidence: 99%

Investigation on heat transfer evaluation for a more efficient two-zone combustion model in the case of natural gas SI engines

Lounici

Loubar

Balistrou

et al. 2011

Applied Thermal Engineering

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International audienceTwo-zone model is one of the most interesting engine simulation tools, especially for SI engines. However, the pertinence of the simulation depends on the accuracy of the heat transfer model. In fact, an important part of the fuel energy is transformed to heat loss from the chamber walls. Also, knock appearance is closely related to heat exchange. However, in the previous studies using two-zone models, many choices are made for heat transfer evaluation and no choice influence study has been carried out, in the literature. The current study aims to investigate the effect of the choice of both the heat transfer correlation and burned zone heat transfer area calculation method and provide an optimized choice for a more efficient two-zone thermodynamic model, in the case of natural gas SI engines. For this purpose, a computer simulation is developed. Experimental measurements are carried out for comparison and validation. The effect of correlation choice has been first studied. The most known correlations have been tested and compared. Our experimental pressure results, supported for more general and reliable conclusions, by a literature survey of many other studies, based on measured heat transfer rates for several SI engines, are used for correlation selection. It is found that Hohenberg's correlation is the best choice. However, the influence of the burned zone heat transfer area calculation method is negligible

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“…One explanation is that a TDC position error has little influence on the cylinder pressure far away from TDC and thus a small estimation interval is favorable. A closely related method is the one described in Reference [7] where the asymmetry of the pressure trace around TDC is analysed using thermodynamic cycle simulation. The TDC position is adjusted until the asymmetry between two arbitrary points in the compression and expansion strokes respectively is correctly reproduced.…”

Section: Introductionmentioning

confidence: 99%

TDC Offset Estimation from Motored Cylinder Pressure Data based on Heat Release Shaping

Tunestål

2011

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

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Résumé -Estimation du décalage de PMH à partir de données de pression de cylindre moteur basées sur la conformation de libération de chaleur -La détermination du décalage de Point Mort Haut (PMH) correct d'un moteur à combustion interne est plus difficile qu'il n'y paraît. Cette étude introduit une nouvelle méthode destinée à déterminer le décalage de PMH sur la base de la simple supposition que la puissance de perte de chaleur à travers les parois de la chambre de combustion soit constante pour des cycles moteur selon un intervalle d'angle de bras de manivelle étroit autour du PMH. La méthode proposée utilise une optimisation des moindres carrés non linéaire pour déterminer la combinaison de rapport de chaleur spécifique et de décalage de PMH qui rend la puissance de perte de chaleur aussi constante que possible. Un sous-problème important consiste à déterminer la localisation de pression de pic avec une haute précision. L'application d'une série de Fourier du troisième ordre à la pression de cylindre moteur permet l'estimation du maximum de pression moyennant un écart-type de 0,005• d'angle de bras de manivelle (AM) et elle peut être également utilisée à la place de la pression mesurée afin de réduire l'incertitude de l'estimation du PMH d'environ 50 %. L'écart-type d'une estimation de PMH de cycle unique est approximativement de 0,025• d'AM lors de l'utilisation d'une résolution de bras de manivelle de 0,2• d'AM pour les mesures. L'erreur systématique de l'estimation de PMH se situe dans la plage allant de 0 à 0,02• d'AM par comparaison à la fois avec les mesures réalisées au moyen d'un détecteur de PMH et avec des cycles moteur simulés. La méthode peut être utilisée à la fois à des fins d'étalonnage et de diagnostics à bord, par exemple pendant un démarrage, une coupure de carburant ou un arrêt du moteur. La série de Fourier du troisième ordre appliquée s'accompagne d'une pénalisation de calcul significative mais, puisqu'elle n'est appliquée que de façon très intermittente, ceci ne doit pas poser un problème sérieux. Abstract -TDC Offset Estimation from Motored Cylinder Pressure Data based on Heat Release Shaping -Finding the correct Top Dead Center (TDC) offset for an internal combustion engine is harder than it seems. This study introduces a novel method to find the TDC offset based on the simple assumption that the heat loss power through the combustion chamber walls is constant for motored cycles in a narrow

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A thermodynamics model for the compression and expansion process during the engine’s motoring and a new method for the determination of TDC with simulation technique

Cited by 12 publications

References 4 publications

Testing of a Modern Wankel Rotary Engine - Part III: Firing Condition Analysis

Testing of a Modern Wankel Rotary Engine - Part III: Firing Condition Analysis

Investigation on heat transfer evaluation for a more efficient two-zone combustion model in the case of natural gas SI engines

TDC Offset Estimation from Motored Cylinder Pressure Data based on Heat Release Shaping

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