Transition and structure of turbulent jet diffusion flame

Abstract

An experimental study on transition and structure of a turbulent jet diffusion flame developing in a coflowing airstream was made using hydrogen and acetylene as fuel gases. These fuels have shown distinct transition mechanisms from a laminar to a turbulent flame. For hydrogen, it is caused as the result of a flow instability very near the axis of fuel free jet, whereas for acetylene it is caused by intermittent fluctuations of the pipe flow inside the injector. In the fully developed turbulent acetylene flame, the small scale fluctuations which are originated inside the injector and are ejected into the free jet, develop as they flow downstream into a large scale eddy motion of luminous flame.