Characteristics of microscale combustion in a narrow heated channel

Abstract

The characteristics of microscale combustion were investigated by using a microchannel heated by an external source. The inner diameter of the channel was 2 mm, which was slightly smaller than the quenching distance of the stoichiometric methane-air mixture under normal conditions. The effects of the equivalence ratio and the averaged flow velocity on the characteristics of combustion in the microchannel were examined. At a channel-wall temperature of approximate to1000degreesC, flames could be stabilized at equivalence ratios of 0.05-1.9 and mixture velocities up to 150 cm/sec in a U-shaped quartz-glass channel. At moderate equivalence ratios and lower velocity conditions within the flammability region, oscillatory combustion was observed. A simple analytical model predicting flame oscillations on the basis of the linear analysis of steady solutions is proposed.