Simulation of flame speed enhancement of a hydrocarbon flame with a microwave field

This study models the effect of microwave electric field on a premixed flame to achieve an accurate prediction of flame speed enhancement by considering non-thermal electron for both kinetics and mass transport. The results compare well against experimental data, and show that using electron energy distribution function (EEDF) to calculate recombination rates of electron is the key to improve the prediction of the electron number density and the flame speed. The resulting technique also agrees well with the flame speed theory to explain the mechanism of flame speed increase by ohmic heating, which is by increasing the flame temperature. The model can also predict the efficiency of flame speed enhancement for a microwave electric field. Finally, the model can be improved by incorporating recombination cross sections of major ions, if they are available. (C) 2019 The Combustion Institute. Published by Elsevier Inc. All rights reserved.