Developed Reduced Reaction Mechanisms for Practical High Hydrocarbon Fuels

Abstract

Reduced chemical kinetic models have been developed to describe the combustion fundamentals for practical high hydrocarbons fuels over a wide range of experimental conditions. The fuels include n-Butane, Benzene. n-Heptane. Gasoline, Kerosene (JP-8), and n-Hexadecane. The mechanism for each fuel includes a single reaction expression for fuel and oxygen to form formaldehyde (CH₂O) and hydrogen (H₂) or carbon monoxide (CO)together with a detailed reaction mechanism for CH₂O-CHO-CO-H₂-O₂ oxidation. These kinetic mechanisms will be as generally applicable as possible and can be used in 2-D or 3-D combustion models to understand the practical combustion and emission problems in engines and furnaces. Each mechanism consists of 13 chemical species with 22 elementary reactions

The present reduced kinetic mechanisms are used in one-dimensional laminar premixed flame model and incorporated detailed representation of transport fluxes to predicted laminar burning velocity and flame structure. These predicted results were compared satisfactorily with the experimental data for each fuel over a wide ranges of equivalence ratio, pressure, and temperature. In addition, the flammability limits for different types of fuels were also examined. A single reaction expression for breakdown each of the above fuels has been driven here, and is used with CH₂O-CHO-CO-H₂-O₂ mechanism to predict satisfactorily the experimental combustion fundamentals for these practical fuels. These mechanisms are only valid from lean to near stoichiometric flames and they also, lead to improve the accuracy of the predicted radical species compared to the past quasi-global model that has assumed CO and H₂ as reactions products. An algebraic expression for burning velocity of each fuels is derived, in terms of equivalence ratio, initial pressure and temperature. and can be used in complex models.