Mixing and diffusion characteristics of blooming jet using DNS

Abstract

A wide variety of applications of jets enhancing mixing, difusing, heating and cooling efficiency have been studied. Mixing and diffusing characteristics markedly depend on outlet conditions of jet. In particular, blooming jets occur with a appropriate superimposition of axial and helical exicitations on an inlet velocity profile. Blooming phenomenon of jets is characterised by vortex rings moving along branches of separate streams. The present study evaluates the mixing performance of blooming jet using direct numerical simulation (DNS). It reveals that the statistical entropy and entrainment rate are obviously greater than that of unexcited jet as well as the momentum transfer of blooming jet is significantly enhanced.