Droplet combustion in electric field is interesting in terms of not only scientific aspects but also combustion control. In this study, single fuel droplets are burned in non-uniform electric filed, which is formed with a needle and flat-plate electrode. Using this system, the effect of electron and/or ion emission from the needle cathode is expected. Effect of the emitted electron and/or ions movements could be discussed comparing with uniform electric field experiments. For comparison, both polarities were tested. All experiments are carried out under microgravity in order to eliminate the natural buoyancy. The distance between the electrodes is 50 mm and direct current voltages applied between them from OkV to 6kV. Ambient gas is air at atmosphere pressure and room temperature. In these conditions, the corona discharge was not observed. The fuel tested is n-octane and ethanol. The results show that the flames are deformed to cathode with applying electric voltages in spite of electric polarity and burning rate constants principally increase with applying voltages. This tendency is similar to experimental result in uniform electric field. For n-octane flame, there are a few differences of flame shapes between both polarities, and it will affect their burning rate constants.
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