Coherent Structures and Turbulent Transport in the Initial Region of Jets and Flame in Swirling Flow

Abstract

This paper presents the results of experimental studies of the spatial flow structure and coherent structures in the initial region of swirling jets at a Reynolds number of 5000 and different swirl rates. The contribution of these structures to the turbulent transport of momentum and mass was first quantitatively evaluated. In addition, for the case of high swirl with vortex core breakdown, the effect of coherent structures on the fluctuation in the local heat release rate due to the deformation of the flame front was investigated for combustion of a methane-air mixtures with an air excess ratio of 1.43.