Ignition studies of fuel droplet streams

Abstract

Experiments have been conducted to identify the importance of transport mechanisms on fuel droplets ignition. An electrically heated flat plate was positioned in front of a vertical stream of decane droplets. The geometry and dynamic of the arrangement was photographically recorded to obtain time and space resolved information. The following results were observed: The ignition event depends on the temperature of the hot surface, the geometry of the arrangement, the physical properties of the fuel, the residence time of the droplets in the thermal boundary layer and the fuel vapor concentration of the carrier gas at room temperature. Comparisons of ignition delay times which translate into ignition delay distances show discrepancy with predicted values. The lack of a radiation heat transfer mechanism in the model and the enhanced convective heat transfer due to the thermal boundary layer of the vertical flat plate are assumed to be the reason for the mismatch between theory and experimental data.