Electrostatic Probe Measurements in Propagating Flames : Part 2, The Relation between Flame Propagation Velocity and Ion Current

Abstract

An experimental study has been made on electrostatic probe measurements in flames propagating through a stoichiometric propane-air mixture in a tube in the initial pressure range from 200 to 500 mm Hg. The ion current records obtained by an electrostatic probe were examined in detail and were compared with the flame behavior recorded on the schlieren photographs taken with a high-speed camera. The results show that the flame behavior inferred from the ion current records coincides well with that observed on schlieren photographs. The maximum ion current was found to increase with the increase of the gas velocity in the high ion density region near the propagating flame front. The phenomena near the turbulent flame front could be understood to some extent from the ion current records.