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1

Relations between ion signal and flame propagation in cylinder of a rapid compression machine

Fiedkiewicz Łukasz, Pielecha Ireneusz

Combustion Engines

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2019

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R. 58, nr 4

264--268

EN

Internal combustion engine diagnostics using traditional methods of cylinder pressure signal processing limits the amount of information available about the combustion process. It is necessary to conduct research in order to obtain more precise information - in-creasing the combustion process diagnosis potential. One such suggestion is the use of an ionization signal and an attempt to link it to the flame development during combustion of gaseous fuels. The article attempts to identify such a relationship using a rapid compression machine due to optical access it provides to the combustion chamber. As a result of the research, the relationships between the ionization voltage (chemical and thermal) of the first combustion phase and the corresponding flame development rates were determined. A relatively high coefficient of determination value was obtained for both relations, which indicates the possibility of obtaining diagnostic information about the combustion process from the ionization signal.

2

Optyczne badania prędkości rozchodzenia się płomienia w komorze spalania przy zasilaniu paliwem CNG

Wisłocki K., Pielecha I., Czajka J., Maslennikov D.

Logistyka

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2009

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nr 6

CD-CD

PL

W artykule przedstawiono badania prędkości rozchodzenia się płomienia w komorze spalania modelowego silnika spalinowego przy zasilaniu paliwem gazowym CNG. W badaniach wykorzystano optyczne metody pomiarowe oraz cyfrową obróbkę materiału zdjęciowego z wykorzystaniem programu DaVis. Obserwacje przeprowadzono dla dwóch wartości współczynnika nadmiaru powietrza oraz różnej intensywności zawirowania obwodowego. Stwierdzono prędkości rozprzestrzeniania się płomienia rzędu 2-16 m/s, mniejsze w początkowej fazie spalania. Wpływ wartości współczynnika nadmiaru powietrza na tą prędkość jest większy w ośrodku bez zawirowania, podczas gdy przy zawirowaniu jego wpływ jest trudny do zaobserwowania.

EN

In the paper the research on flame propagation velocity in the model of combustion engine fueled with CNG has been presented. In the research both optical investigation methods and digital processing of the photographic material by means of the DaVis program have been used. The observation has been conducted for two different lambda-value and different intensities of the swirling mixture motion. The flame front velocities of 2-16 m/s have been detected, smaller ones in the beginning phases of combustion. The influence of the fuel-air ratio on the flame front velocity seems to be bigger when the swirling motion is smaller, and by bigger swirl influence of the fuel-air ratio would be difficult to be stated.

3

Flame quenching by the wall-fundamental characteristics

Gutkowski A., Tecce L., Jarosiński J.

Journal of KONES

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2007

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Vol. 14, No. 3

203-210

EN

Knowledge of flame-wall interaction allowed us to understand the phenomena of near wall combustion and flame extinction. The study of near wall flame propagation is important because it is related to engineering applications, such as possible misfiring in internal combustion engines, optimization of combustion, and reduction of unburned hydrocarbons in the combustion products. In the present work different characteristics of the quenching distance were measured in square narrow quenching channels. The channel widths were changed from 2.5mm to 15mm, their length being 30cm. Propane/air mixture was employed in experiments. Direct visualization has been used to observe flame behaviour under quenching conditions. Numerical simulation revealed structure of limit flames during their propagation in quenching channels. It was found satisfactory agreement between numerical calculations and experiments. In conclusions it was confirmed that flame quenching depends on the relation between heat release rate to heat loss rate. Dead space appeared to be larger for rich mixtures in comparison with the lean ones. Flame curvature reached maximum value for stoichiometry and decreased for leaner or richer mixtures.