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Flame-wall interaction is an important phenomenon on combustors. Especially, the influence of wall on the flame characteristics in small scale combustors becomes larger than that on normal scale ones because of their large surface-to-volume ratio. In this study, the influence of surface reaction and heat-loss on radical distributions and heat release rate of propane-air mixture is investigated using numerical simulation. A two-dimensional slit burner between two parallel plates is modeled. The distance between the plates is changed, and the profiles are obtained for both active wall, which is considered surface reaction causes radical quenching, and inert wall conditions. As a result, it is found that heat release rate for active wall condition is smaller than that for inert wall condition while the reactant consumption rate is the same for active and inert wall conditions. It is because that the radical which distribute widely near the wall like OH is quenched by surface reaction before be used in gas phase reaction. Thus, the blow off distance for active wall with high wall temperature condition is larger than that for inert wall condition. For low wall temperature condition, since the influence of surface reaction is negligibly small as compared with that of heat-loss, the distance is the same value for active and inert wall conditions.

In this study, we experimentally examined a combustion field in a triple port burner. There are four flame configurations, consisting of attached flames, inner attached/outer lifted flames, inner lifted/outer attached flames, and twin lifted flames. Focusing on the transition process of these flames, the flow field was investigated when the external air flow velocity was increased at constant internal air flow and fuel flow velocities. Results show that, except for the attached flame, when the flame is lifted, the axial velocity toward the leading-edge flame gradually decreases downstream, takes its minimum, and then increases very rapidly. This minimum velocity is larger than the so-called laminar burning velocity. It should be noted that, different from a single lifted flame, the inner or outer flame is affected by the other flame located more upstream. For example, the downstream lifted flame faces the flow induced by the upstream lifted flame. Resultantly, a unique behavior of flip-flop between inner and outer flames is observed.