Sensitivity of propagation and extinction of large hydrocarbon flames to fuel diffusion

Detailed flame simulations require the use of both chemical kinetics and molecular transport. Compared to kinetics, notably less work has been done to assess the validity of transport properties and their effect on the results of flame simulations. In the present study, transport parameters were proposed for n-alkanes Lip to tetradecane and I-alkene up to dodecene, based oil the correlations of corresponding states. The effect of molecular diffusion was illustrated by considering the phenomena of propagation and extinction for flames of n-dodecane, a main component of surrogates of practical jet fuels. Sensitivity analyses were performed on the reaction rates and binary diffusion coefficients and the relative importance of chemical kinetics and transport properties on flame propagation and extinction was quantified. The effect of carbon number on the extinction of non-premixed n-alkane flames was addressed also based on transport effects. (C) 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.