https://hal.archives-ouvertes.fr/hal-00288708/document

Detailed chemical kinetic models for the low-temperature combustion of hydrocarbons with application to gasoline and diesel fuel surrogates

The ignition, oxidation, and combustion of kerosene: A review of experimental and kinetic modeling

Computational fluid dynamic (CFD) simulations that include realistic combustion/emissions chemistry hold the promise of significantly shortening the development time for advanced high-efficiency, low-emission engines. However, significant challenges must be overcome to realize this potential. This paper discusses these challenges in the context of diesel combustion and outlines a technical program based on the use of surrogate fuels that sufficiently emulate the chemical complexity inherent in conventional diesel fuel. The essential components of such a program are discussed and include: (a) surrogate component selection; (b) the acquisition or estimation of requisite elementary chemical kinetic, thermochemical, and physical property data; (c) the development of accurate predictive chemical kinetic models, together with the measurement of the necessary fundamental laboratory data to validate these mechanisms; and (d) mechanism reduction tools to render the coupled chemistry/flow calculations feasible. In parallel to these efforts, the need exists to develop similarly robust models for fuel injection and spray processes involving multicomponent mixtures of wide distillation character, as well as methodologies to include all of these high fidelity submodels in computationally efficient CFD tools. Near- and longerterm research plans are proposed based on an application target of premixed diesel combustion. In the near term, the recommended surrogate components include n-decane, iso-octane, methylcyclohexane, and toluene. For the longer term, n-hexadecane, heptamethylnonane, n-decylbenzene, and 1-methylnaphthalene are proposed.

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Development of an Experimental Database and Kinetic Models for Surrogate Diesel Fuels

Studies of aromatic hydrocarbon formation mechanisms in flames: Progress towards closing the fuel gap

https://dr.ntu.edu.sg/bitstream/10220/24197/1/RECENT%20DEVELOPMENTS%20IN%20THE%20FIELD%20OF%20FIRE%20RETARDANCY%20OF%20POLYMERIC%20MATERIALS.pdf

Recent developments in the fire retardancy of polymeric materials

This study was aimed at comparing the chemical structure of two rich premixed flames Ted respectively with a neat fuel: n-decane and a multi-component fuel, kerosene. Both flames were stabilized on a flat-flame burner at atmospheric pressure. Samples were withdrawn along the symmetry axis with a quartz microprobe and analyzed by gas phase chromatography. The main objective was to justify, for a future modelling purpose, the use of a detailed reaction mechanism validated in the n-decane flame to predict the chemical structure of a kerosene flame. A close similitude was observed for the mole fraction profiles of both major species and main intermediates measured in each flame. Relative concentrations of the intermediate species in the n-decane flame can be interpreted qualitatively by β-scission of large alkyl radicals. The only marked difference observed when changing the fuel concerns benzene. The maximum mole fraction measured in the kerosene flame: 1.05·10−3 exceeds by one order of magnitude, t...

Chemical Structure of Atmospheric Pressure Premixed n-Decane and Kerosene Flames

Thermal degradation of PMMA subjected to a radiant heat flux was studied both experimentally and numerically. Very accurate measurements of mass loss rate and temperature profiles were performed for three constant heat fluxes: 1.5,2.3 and 3.0 W·cm-'. The results show that the mass loss rate cannot be directly related to the surface temperature and a contribution of the sub-surface region of the sample to the rate of gasification must be taken into account in a thermal degradation odel. A heat source term was introduced in the conduction equation and a kinetic equation was used to locally calculate the mass loss rate in each slab of the solid. The density and the thermal conductivity of the material were assumed temperature independent while for the specific heat the values measured by differential scanning calorimetry in the range 20-400·C were retained. The predictions of the model are in very close agreement with the experimental results for the evolution with time of both the temperature profi...

Experimental and Numerical Study of the Thermal Degradation of PMMA

There is a need for prediction models of soot particles and polycyclic aromatic hydrocarbons (PAHs) formation in parametric conditions prevailing in automotive engines: large fuel molecules and high pressure. A detailed kinetic mechanism able to predict the formation of benzene and PAHs up to four rings from C 2 fuels, recently complemented by consumption reactions of decane, was extended in this work to heptane and iso -octane oxidation. Species concentrations measured in rich, premixed flat flames and in a jet stirred reactor (JSR) were used to check the ability of the mechanism to accurately predict the formation of C 2 and C 3 intermediates and benzene at pressures ranging from 0.1 to 2.0 MPa. Pathways analyses show that propargyl recombination is the only significant route to benzene in rich heptane and iso -octane flames. When included as the first step of a soot particle formation model, the gas-phase kinetic mechanism predicts very accurately the final soot volume fraction measured in a rich decane flame at 0.1 MPa and in rich ethylene flames at 1.0 and 2.0 MPa.

Modelling of aromatics and soot formation from large fuel molecules

Investigating the role of methane on the growth of aromatic hydrocarbons and soot in fundamental combustion processes

The formation of frequently discussed soot precursors has been compared in decane and kerosene flames A specific study on the influence of equivalence ratio on the formation of some species (acetylene, benzene, vinyl benzene and phenyl acetylene) showed that in decane flames aromatic hydrocarbons are formed from acetylene whereas in kerosene flames the main source is the aromatic part of the fuel From this result it seems to be reasonable to represent kerosene as a mixture of decane (90%) and toluene (10%) when developing a detailed kinetic mechanism to predict benzene formation in flames burning kerosene The mechanism was checked by comparison of computed mole fraction profiles with measured profiles of a sooting kerosene-oxygen-argon flame with an equivalence ratio of 22 and of a decane flame with the same equivalence ratio

J.L. Delfau

Papers

Chemical Structure of Atmospheric Pressure Premixed n-Decane and Kerosene Flames

Experimental and Numerical Study of the Thermal Degradation of PMMA

Modelling of aromatics and soot formation from large fuel molecules

Investigating the role of methane on the growth of aromatic hydrocarbons and soot in fundamental combustion processes

Formation of Aromatic Hydrocarbons in Decane and Kerosene Flames at Reduced Pressure