Laminar burning velocities of n-heptane, iso-octane, ethanol and their binary and tertiary mixtures

Lipzig, van Jpj; Nilsson, Erik; Goey, de Lph Philip; Konnov, Alexander A.

doi:10.1016/j.fuel.2011.04.029

Cited by 205 publications

(132 citation statements)

References 39 publications

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“…First, measurements performed by van Lipzig et al 8 were used to compare different mixing rules because these measurements were performed using a flat plate burner and the heat flux method resulted in an accuracy of ±1 cm/s. Calculations were made for equivalence ratios of 0.7−1.3, but in Figures 1 and 2, the minimum equivalence ratio is 0.9 for the clarity of the figures and because the difference in laminar burning velocity in the 0.7−0.8 range was 2 cm/s at its maximum.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Alternative Fuels for Spark-Ignition Engines: Mixing Rules for the Laminar Burning Velocity of Gasoline–Alcohol Blends

et al. 2012

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Experimental measurements of the laminar burning velocity are mostly limited in pressure and temperature and can be compromised by the effects of flame stretch and instabilities. Computationally, these effects can be avoided by calculating one-dimensional, planar adiabatic flames using chemical oxidation mechanisms. Chemical kinetic models are often large, complex and take a lot of computation time, and few models exist for multi-component fuels. The aim of the present study is to investigate if simple mixing rules are able to predict the laminar burning velocity of fuel blends with a good accuracy. An overview of different mixing rules to predict the laminar burning is given and these mixing rules are tested for blends of hydrocarbons and ethanol. Experimental data of ethanol/n-heptane and ethanol/n-heptane/iso-octane mixtures and modeling data of an ethanol/nheptane blend and blends of ethanol and a toluene reference fuel are used to test the different mixing rules. Effects of higher temperature and pressure on the performance of the mixing rules are investigated. It was found that simple mixing rules that consider only the change in composition are accurate enough to predict the laminar burning velocity of ethanol/hydrocarbon blends. For the blends used in this study, a Le Chatelier's rule based on energy fractions is preferable because of the similar accuracy in comparison to other mixing rules while being more simple to use.

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Section: ■ Results and Discussionmentioning

confidence: 99%

“…Hirasawa et al 7 measured the laminar burning velocity of binary blends of ethylene + n-butene, ethylene + toluene and n-butane + toluene. Van Lipzig et al 8 considered binary and ternary mixtures of nheptane, iso-octane and ethanol. Broustail et al 9 performed measurements with mixtures of butanol and ethanol with isooctane.…”

Section: ■ Introductionmentioning

confidence: 99%

Alternative Fuels for Spark-Ignition Engines: Mixing Rules for the Laminar Burning Velocity of Gasoline–Alcohol Blends

et al. 2012

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“…34 It was shown that the ratio of the flows via MFC-1 (carrier gas for the CEM) and MFC-2 (balance) does not affect the measured burning velocity within the expected accuracy of the measurements. No influence of the CEM operating temperature was observed when it was set well above boiling temperatures of methanol (423 K in the present work).…”

Section: ■ Error Assessmentmentioning

confidence: 92%

“…The present experimental rig is similar to that used by Konnov et al 19 and has been constructed and certified in previous work. 34 The experimental setup for the adiabatic flame stabilization using the heat flux method is shown in Figure 3. A 2 mm thick burner plate perforated with small holes (0.5 mm in diameter) is attached to the burner outlet (see Figure 1).…”

Section: ■ Introductionmentioning

confidence: 99%

Temperature Dependence of the Laminar Burning Velocity of Methanol Flames

Vancoillie

Christensen²,

Nilsson³

et al. 2012

Energy Fuels

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To better understand and predict the combustion behavior of methanol in engines, sound knowledge of the effect of the pressure, unburned mixture temperature, and composition on the laminar burning velocity is required. Because many of the existing experimental data for this property are compromised by the effects of flame stretch and instabilities, this study was aimed at obtaining new, accurate data for the laminar burning velocity of methanol−air mixtures. Non-stretched flames were stabilized on a perforated plate burner at 1 atm. The heat flux method was used to determine burning velocities under conditions when the net heat loss from the flame to the burner is zero. Equivalence ratios and initial temperatures of the unburned mixture ranged from 0.7 to 1.5 and from 298 to 358 K, respectively. Uncertainties of the measurements were analyzed and assessed experimentally. The overall accuracy of the burning velocities was estimated to be better than ±1 cm/s. In lean conditions, the correspondence with recent literature data was very good, whereas for rich mixtures, the deviation was larger. The present study supports the higher burning velocities at rich conditions, as predicted by several chemical kinetic mechanisms. The effects of the unburned mixture temperature on the laminar burning velocity of methanol were analyzed using the correlation u L = u L0 (T u /T u0 ) α . Several published expressions for the variation of the power exponent α with the equivalence ratio were compared against the present experimental results and calculations using a detailed oxidation kinetic model. Whereas most existing expressions assume a linear decrease of α with an increasing equivalence ratio, the modeling results produce a minimum in α for slightly rich mixtures. Experimental determination of α was only possible for lean to stoichiometric mixtures and a single data point at ϕ = 1.5. For these conditions, the measurement data agree with the modeling results.

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“…As presented by numerous sources in previous researches, among the conditions that influence the liquid length are the nozzle diameter [25,40,41], the air density and temperature [25,26,[39][40][41][42][43][44][45][46], and the fuel properties [25,31,39,40,47]. The injection pressure, on the other hand, seems to have an almost negligible effect on the penetration of the liquid core [25,26,[41][42][43][44]48].…”

Section: Liquid Lengthmentioning

confidence: 95%

An experimental study of the effects of fuel properties on diesel spray processes using blends of single-component fuels

Fajardo¹,

Martin²

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Resumen.Estosúltimos años, la tendencia en motores diesel ha sido la de emplear distintos tipos de combustibles para identificar su influencia y comportamiento sobre las emisiones y rendimiento. Dentro de la amplia variedad de combustibles empleados están los llamados combustibles de referencia (PRFs ingl. Primary Reference Fuels), los cuales representan el comportamiento del diesel y la gasolina en lo que respecta a propiedades de encendido, ya que se encuentran en ambos extremos de la escala del número de octano y también poseen números de cetano muy distintos. Una de las desventajas de utilizar gasolina pura o mezclas de diesel-gasolina en motores diesel es el tiempo que toma la mezcla en encender y quemar completamente el combustible. Esto generalmente requiere trabajar con cargas parciales o cargas premezcladas.Para poder aislar los efectos del combustibles sobre los procesos de un chorro y que sea capaz estudiar los parámetros característicos de tiempo de retraso de encendido, longitud de despegue de llama, penetración de líquido y vapor, entre otros, se han realizado distintos experimentos bajo variaciones paramétricas de condiciones de motor diesel. Los ensayos han sido realizados bajo condiciones inertes y reactivas en un motoróptico de dos tiempos y una instalación de alta presión y alta temperatura de flujo continuo a presión constante (CPF ingl. Constant-Pressure Flow ) empleando toberas mono-orificio, con aplicación de diversas técnicaś opticas. Para estudiar la influencia de las propiedades de los combustibles se utilizaron distintos mono-componentes, así como mezclas binarias y un sustituto de diesel conformado por seis componentes, el cual fuel comparado con diesel convencional. Adicionalmente, los resultados han sido contrastados con un modelo unidimensional para ayudar a explicar los valores y tendencias encontrados.Los resultados presentaron una fuerte dependencia de las propiedades de los combustibles en los ensayos realizados bajo condiciones inertes y reactivas. La diferencia entre las propiedades físicas del n-decano y n-hexadecano mostraron una reducción casi lineal sobre la longitud líquida estabilizada hasta aproximadamente un 60 % bajo ciertas condiciones. Adicionalmente, debido a la composición del combustible de sustitución, el n-hexadecano puro demostró tener características de evaporación prácticamente idénticas, probándose a sí mismo como un buen candidato para ser un sustituto mono-componente del diesel convencional. De una manera similar, las propiedades químicas de los PRFs n-heptano e iso-octano también probaron tener influencia sobre el desarrollo del chorro y radiación emitida. Se obtuvieron valores de tiempo de retraso con diferencias de hasta un orden de magnitud entre ambos extremos del rango de las mezclas, así como longitudes de despegue de llama hasta tres veces más largas. La radiación emitida por la incandescencia del hollín presentó las variaciones más altas, ya que algunas condiciones mostraron reducciones de hasta cuatroórdenes de magnitud dentro del rango de mezc...

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Laminar burning velocities of n-heptane, iso-octane, ethanol and their binary and tertiary mixtures

Cited by 205 publications

References 39 publications

Alternative Fuels for Spark-Ignition Engines: Mixing Rules for the Laminar Burning Velocity of Gasoline–Alcohol Blends

Alternative Fuels for Spark-Ignition Engines: Mixing Rules for the Laminar Burning Velocity of Gasoline–Alcohol Blends

Temperature Dependence of the Laminar Burning Velocity of Methanol Flames

An experimental study of the effects of fuel properties on diesel spray processes using blends of single-component fuels

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