Highly turbulent premixed flames stabilied in a co-axial jet flame burner

A co-axial jet flame configuration is found to provide a stable turbulent premixed flame for a wide range of turbulence conditions up to u′/S_L of 20 and higher, for an outer to inner diameter ratio of 8 in the current burner. This flame configuration supports premixed flames in flows with initial mean flow velocity in xcess of 150 m/s. Thus, this arrangement can be used for premixed flame stabilization for large flow velocities and for investigations of turbulent premixed flames over a wide range of turbulence properties, with u′/S_L exceeding 10 in a steady jet flame. An increase in inner jet velocity increases the turbulence intensity, and a gradual increase in the turbulence intensity from the outer flame to the inner flame acts to stabilize the flames. Flame surface properties such as the flame perimeter ratio and flame curvature statistics are also obtained, where the flame curvature exhibits a nearly symmetric PDF at high turbulence levels in spite of the jet flame geometry.