TRANSPORT-PROPERTIES OF POLYCYCLIC AROMATIC-HYDROCARBONS FOR FLAME MODELING

A method for systematic evaluation of the Lennard-Jones parameters for polycyclic aromatic hydrocarbon (PAH) compounds is presented, in which correlations for these parameters are derived using a group contribution technique for critical temperatures and pressures and the Tee-Gotoh-Stewart correlations of corresponding states. The Lennard-Jones self-collision diameters and well depths of 29 PAHs were estimated using this approach and are shown to correlate with the molecular weights of aromatics. The gaseous binary diffusion coefficients of aromatics in common gases were calculated with Chapman-Enskog equation using the estimated Lennard-Jones parameters and were found to compare well with the available experimental data and the predictions of one of the most reliable empirical approximations. The effect of ordinary diffusion of PAH species on their predicted concentration profiles in a 20-torr laminar premixed acetylene flame is demonstrated computationally.