Stabilization of an inverted propane-air flame on a string stretched along the flow

The stabilization conditions for an inverted flame on a long thin string stretched along the cylindrical burner axis were studied experimentally. Gas temperature distributions in the inverted flame are obtained. The boundaries of stable combustion that are simultaneously the condition of excitation of acoustic self-oscillations of the flame are found. Inverted flame blow-off velocities are measured, and the variation of its geometrical characteristics are studied. It is found that during overturning of the flame relative to the vector of the acceleration due to gravity, stabilization of the inverted flame in the open atmosphere is impossible. The physical mechanism involved in the formation of the inverted flame in flow parallel to the stabilizer surface is considered. The role of the hydrodynamic stretching of the flame in flame blow-off and extinction is determined.