抄録
Extinction and stability of micro-scale diffusion flames (we call 'microflame') established over a circular jet burner in atmospheric air is studied numerically. By imposing adiabatic condition for burner surfaces, artificial heat loss in the system is excluded. Flame extinction focused in the present study is lead by size effect. Numerical model considered in the present study includes the convective-diffusive heat and mass transport as well as one-step finite rate chemical reaction. Our numerical results show that extinction is finally achieved in the order of tens micron of burner port, and hundreds micron of flame size (∿ typical reaction layer thickness of hydrocarbon flames). As the size gets extensively smaller, diffusive transport rate becomes very fast while the reaction rate is kept constant irrespective of the size. This discrepancy must be a reason for extinction in the small size limit.
