A Digital Computer Simulation for Spark-Ignited Engine Cycles

Patterson, Donald J.; Wylen, Gordon John Van

doi:10.4271/630076

Cited by 37 publications

(10 citation statements)

References 2 publications

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“…A modification to two-zone (burned-gas, unburned-gas) models (Patterson and Van Wylen, 1963;Krieger and Borman, 1966) of the combustion event is useful in the context of end-gas knock: specifically, a distinct initial thermodynamic state (at Downloaded by [Michigan State University] at 03:24 08 February 2015 ignition) and (more importantly) a distinct polytropic-law exponent (for subsequent evolution of the thermodynamic state) characterize the final portion of the charge to undergo chemical conversion. Thus, for analytic purposes, the unburned charge at time zero is split into so-called "bulk" unburned gas and unburned end gas, each part being spatially uniform and temporally evolving, but the two parts being in general at different thermodynamic states at all times.…”

Section: Three-zone Treatment Of the Combustion Event 2a Preliminariesmentioning

confidence: 99%

Heat Transfer as a Determent of End-Gas Knock

Carrier

Fendell

Fink

et al. 1984

Combustion Science and Technology

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Compressive preheating of the residual charge in an Otto-cycle-type, internalcombustion-engine cylinder can result in autoignition and rapid homogeneous burning (explosion). That is, the final portions of the combustible premixture may convert exothermically to product so rapidly that the reaction time may be less than the acoustic-adjustment time, In such cycles, large spatial nonuniformity in the pressure field, and onset of knock, result-s-events potentially damaging to cylinder components. Since operation at high compression ratio is thermally efficient, since (equally important) knock-free performance at conventional compression ratio is desirable, and since use of knock-inhibiting fuel additives is environmentally constrained, the end-gas-cooling characteristics required to achieve smooth flame propagation are studied, Specifically, a threezone model of the nonisobaric combustion event in a variable-volume enclosure is developed. The three zones are: the burned gas, the unburned charge in the normally cooled region, and the unburned charge in the region with augmented cooling. The heat transfer in these zones is distinguished by locally applicable polytropic relations, which prove to be tractable means of parametrically introducing heat transfer into this highly simplified unsteady one-dimensional model. The results indicate that augmented heat transfer from the end gas can prevent those temperatures for which autoconversion is likely to arise in the residual charge. At moderate engine speed (-2000 rpm), if ignition and final burn-up occur roughly symetrically with respect to piston-crown displacement from top dead center, for the prevention of knock, the fraction of the combustible mass that must be regarded as end gas (and subjected to enhanced cooling by heat transfer) is approximately one-half.

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Section: Three-zone Treatment Of the Combustion Event 2a Preliminariesmentioning

confidence: 99%

Heat Transfer as a Determent of End-Gas Knock

Carrier

Fendell

Fink

et al. 1984

Combustion Science and Technology

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“…Because specifically for combustion and, in general, chemically reactive systems, second law analysis allows the calculation of reaction irreversibility, i.e., the amount of fuel exergy which is destroyed during the irreversible chemical reaction and cannot be converted to work due to entropy increase, something that is not evident from simple first law analysis. A pioneering work on second law analysis of internal combustion engines was reported by Patterson and Van Wylen [6]. They described an early version of thermodynamic cycle simulation for SI engines in which they included the determination of entropy values.…”

Section: Introductionmentioning

confidence: 99%

Second Law Assessment of a Wet Ethanol Fuelled HCCI Engine Combined With Organic Rankine Cycle

Khaliq

Trivedi²

2012

Journal of Energy Resources Technology

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In this study, first and second law analyses of a new combined power cycle based on wet ethanol fuelled homogeneous charge compression ignition (HCCI) engine and an organic Rankine cycle are presented. A computational analysis is performed to evaluate first and second law efficiencies, with the latter providing good guidance for performance improvement. The effect of changing turbocharger pressure ratio, organic Rankine cycle (ORC) evaporator pinch point temperature, turbocharger compressor efficiency, and ambient temperature have been observed on cycle's first law efficiency, second law efficiency, and exergy destruction in each of its component. A first law efficiency of 41.5% and second law efficiency of 36.9% were obtained for the operating conditions (To = 300 K, r" = 3, f]j = 80%). The first law efficiency and second law efficiency of the combined power cycle significantly vaiy with the change in the turbocharger pressure ratio, but the change in pinch point temperature, turbocharger efficiency, and ambient temperature shows small variations in these efficiencies. Second law analysis demonstrates well how the fuel exergy is used, lost, and reused in all of the cycle components. It was found that 78.9% of the total input exergy is lost: 2.0% to the environment in the flue and 76.9% due to irreversibilities in the components. The biggest exergy loss occurs in the HCCI engine which is 68.7%, and the second largest exergy loss occurs in catalytic converter, i.e., nearly 3.13%. Results clearly show that performance evaluation based on first law analysis alone is not adequate, and hence more meaningful evaluation must include second law analysis.

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“…However, a number of maior assumptions are often made in order to simplify the equations and obtain simple analytical solutions (cf., e.g., Krieger and Borman, 1966;Lavoie, Heywood, and Keck, 1970;Harrington, 1975;Danieli, Keck, and Heywood, 1977;McCuiston, Lavoie, and Kauffman, 1977). When accuracy is a requirement, then numerical techniques are adopted (cf., e.g., Patterson and Van Wylen, 1964;Tabaczynski, Ferguson, and Radhakrishnan, 1977).…”

Section: Introductionmentioning

confidence: 99%

Energy and Entropy Balances in a Combustion Chamber: Analytical Solution

Beretta

Keck

1983

Combustion Science and Technology

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Abstract-An analytical solution of the energy and entropy balance equations for a combustible gas mixture contained in an open combustion chamber, for example of an internal combustion engine, is presented. The solution is free of maior assumptions and is in a form suitable for incorporating any detailed models for the effects of wall heat transfer, wall thermal boundary layer, nowuniform temperaturedistributions in the burnt mixture, crevice regions, mass exchange through the boundaries of the chosen control volume and other similar effects. Explicit expressions for the instantaneous mass of burnt mixture and for the entropy generated by irreversibility are presented as functions of pressure and volume history of the combustion chamber and properties of the gas mixtures.

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A Digital Computer Simulation for Spark-Ignited Engine Cycles

Cited by 37 publications

References 2 publications

Heat Transfer as a Determent of End-Gas Knock

Heat Transfer as a Determent of End-Gas Knock

Second Law Assessment of a Wet Ethanol Fuelled HCCI Engine Combined With Organic Rankine Cycle

Energy and Entropy Balances in a Combustion Chamber: Analytical Solution

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