Influence of an Electric Field on the Burning Behavior of Solid Fuels and Propellants

Abstract

An experimental study on the effects of an applied external electric field on the combustion behavior of solid fuels and solid propellants has been conducted. In an opposed flow burning configuration, application of an electric field was shown to extinguish a paraffin fuel and gaseous oxygen flame over a broad range of operating conditions. When subjected to the electric field, burning paraffin fuel strands were found to extinguish at various axial locations relative to the exit of the oxidizer gas jet. Extinguishment location was found to be a function of field strength as well as electrode surface area, while changes in polarity did not significantly alter the results. In addition, the combustion behaviors of two composite solid rocket propellants were studied while subjected to an external electric field. Both propellants were based on HTPB/AP combinations, with one propellant containing aluminum and the other being non‐aluminized. Application of an electric field to the composite solid rocket propellant strands demonstrated decreases in propellant burning rate under all operating conditions for both propellants including changes in polarity. The flame structure of the aluminized propellant was examined closely as the luminosity, flame length, and flame width varied significantly with field strength and burning location of the strand relative to the electrodes.

Universal Concept of Self-Synchronization of the Micro/Nano- Structures of the Energetic Materials Reactionary Zones and Micro-Scale Combustion Mechanisms

“…In general, the application of electric fields to a combusting solid propellant has shown to increase the burning rate of the propellant, and even under certain conditions can decrease the burning rate as well [22]. In particular, application of an electric field changes the burning surface roughness [22], i.e. modifies the process of excitation of the micro/nanostructures in the reactionary zones.…”

“…An experimental study was conducted to determine the effects of an external DC electric field on the combustion behavior of solid fuels and solid propellants [22]. In an opposed flow configuration, a paraffin wax fuel was observed to extinguish when an electric field was applied over a wide range of conditions.…”

“…Researchers have assumed that the results of the paraffin fuel study can be attributed most likely to effects of an ionic wind driving the flame front away from the fuel surface, thus not allowing sufficient heat feedback for continuous fuel pyrolyzation. The burning rates of two composite solid rocket propellants were also studied under the influence of an external DC electric field [22]. Both propellants were based on hydroxyl terminated polybutadiene and ammonium perchlorate where one has a specified amount of aluminum.…”