This paper reports results of experimental and numerical investigations of ethanol-air diffusion flames and partially premixed flames at an air-side strain rate of 100 s−1, in a counterflow geometry. The diffusion flame consists of prevaporized fuel, with mole fraction of 0.3, diluted with nitrogen in the fuel stream, and plant air as the oxidizer stream. The partially premixed flame includes prevaporized fuel in air partially premixed to an equivalence ratio of 2.3 in the fuel stream, and plant air as the oxidizer stream. Temperature profiles were measured by thermocouple, and concentration profiles of the stable species C2H5OH, CO, CO2, H2, H2O, O2, N2, CH4, C2H6, and C2H2+C2H4 were measured by gas chromatography of samples withdrawn by a fine probe. Computational studies involved numerical integration of the conservation equations, with detailed chemistry, transport and radiation effects included, to calculate the structures of the counterflow flames. A chemical-kinetic mechanism consisting of 235 elementary steps and 46 species with recently published reaction-rate parameters was developed and tested for these flames. The proposed mechanism, which produces reasonable agreement with previous measurements of ignition, freely propagating premixed flames and diffusion-flame extinction, also yields good agreement with much of the present data, although there are quite noticeable differences between predicted and measured peak C2H6 concentrations. These differences and the desirability of additional tests of other predictions and of tests under other conditions motivate further research.
An analytic probability density function for partially premixed flames with detailed chemistry
