通常スケールの火炎端特性から考察するマイクロフレームの安定性

抄録

  This paper studied a normal scale lifted flame base (triple flame), which has remarkable leading edge characteristics, in order to investigate microflame stability. A simple theoretical analysis was performed using velocity profiles measured with particle image velocimetry (PIV) and temperature profiles measured with a thermocouple. Two-dimensional numerical calculations were also performed with a C1 chemistry reaction model. The maximum burning velocity change in the flame curvature can be reproduced by present theory considering flame stretch effects, but this velocity is not consistent with experiment results. However, numerical calculations with sufficient spatial resolution yield velocities consistent with experiments. These calculation results demonstrate that the reaction of CH₃ formation with an H radical is accelerated at the leading edge of the flame. This reaction mechanism is identical to that for microflame stability, which is estimated through the usual numerical approach. Namely, the stability of the microflame is enhanced by the generated H radical. This stability mechanism is basically the same as that for the normal flame base.