The influence of electric fields on combustion has been studied since the late nineteenth century. As early as 1899, it was known that electric fields could be utilized to modify flame geometry, as reported by Chattock [3]. Since that time, a number of the effects induced by electric fields on flames have been investigated, including premixed flame speed modifications [15,16-18,21,27,28,31,32], flame blowoff flow rate changes [6,11,12], variations in flame stability [2], and alterations to emissions [29,30,33]. Numerical models have been created to model and simulate these effects in the pursuit of better understanding of the phenomena [1,13]. A commonly referenced explanation for the influence of electric fields on flame behavior is ionic wind, where charged ions and electrons within the flame sheet are impacted by the presence of an electric field. The enhanced motility of these ions and electrons in the direction of the electric field lines modifies flame behavior depending on the orientation of the electric field and the type of field applied. Alternate theories and experiments suggest that energy may be directly applied to flame fronts by electric means [4,5,19,20], particularly examining the enhancement of flames by very high frequency (MHz to GHz) electric fields. The electric field effect on quenching distance seems to be a particular focus area that is missing from the literature. It may be that the quenching diameter was assumed to be inversely proportional to the flame speed, which would reduce the necessity for such a study. Flame phenomena on the millimeter scale are of great concern in the field of miniature combustion and power generation systems. The high energy density of hydrocarbon fuels make them an attractive alternative to batteries for portable power [4,7,24,25] but development of such systems is greatly complicated by heat losses leading to quenching [9,22,25]. In addition to problematic heat losses, some miniature combustor designs exhibit inherent instabilities [8,34]. The ability to rapidly modulate the combustion process by electric means may provide novel means by which to mitigate oscillations and regain control of otherwise unstable process. If the observed electric enhancement of combustion processes can translate to miniature reactors it may facilitate the design of lightweight power supplies to replace conventional batteries.
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