Paper Title
COUNTERFLOW FLAME INTERACTION AROUND TWIN POROUS CYLINDRICAL BURNERS ARRANGED SIDE-BY-SIDE

Abstract
Abstract - This reaearch adopts a multi-block grid combustion model to simulate the flame interaction over binary Tsuji burners. Intercylinder spacing (L) and inflow velocity (Uin) influences are studied. In general, as L becomes wider, the flame transition velocity is decreased, which transforms the envelope flame into the wake flame. However, the combustion efficiency raises with L. The dual envelope diffusion flames merge into a bigger one thoroughly as L <= 1.5D. There is only one vortex behind each cylinder as L = 1.5D or 2D. However, none vortex behind each cylinder at L = 1.2D. As L >= 3.5D, none interference between the twin flames. The oxygen deficiency between the twin flames is the controlling mechanism of mutual interaction for dual counterflow diffusion flames. In the case of varying Uin under fixed L = 3D, as Uin raises to 0.79 m/sec, the twin envelope diffusion flames transform into twin wake flames. As Uin further raises to 1.96 m/sec, the dual wake flames extinguish. Increasing the inflow velocity can enhance the mutual interaction between twin envelope flames. The bigger the inflow velocity, the lower the flame temperature due to the flame stretch effect. Besides, three vortices are found behind each burner as flames are near extinction, and this is extremely different from other cases. As L is fixed, the twin flames have a trend to attract each other normally due to the mutual interaction between them. However, as the inflow velocity raises to near extinction limit, the twin flames repel each other. Keywords - Tsuji Burner, Flame Interaction, Multi-Block Grid