Wrinkling, pocket formation, and double premixed flame interaction processes

An experimental method of investigation is used to analyze some fundamental features of a double laminar premixed flame interacting with a single vortex ring. A steady double premixed counterflow flame of propane and air is first established between two opposed nozzles. A vortex ring is generated from a cylindrical tube installed in the lower combustor nozzle and impinges on one flame if the vortex is weak and on both flames if not. The interaction between the toroidal vortex and the lower flame provides complementary information on the fundamental interaction processes previously studied by Driscoll and coworkers. Comparisons with the numerical simulations of Poinsot et al, are made and confirm the theoretical predictions. The interaction between the vortex and the upper reactive layer is alos interesting as it gives information on the dynamics of two colliding premixed flames and can be used to investigate flamefront mutal interaction processes. The ability of the vortex to reach the second flame front is characterized by a new number Tt(r) , and flame merging processes are discussed.

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