Effects of a directed co-flow on a non-reactive turbulent jet with variable density

In the present study, the effects of a directed co-flow on the process of mixture jet with variable density have been investigated numerically. Three density ratios were considered namely Rρ=0.55, 1.5 and 1.52, respectively, for binary mixtures methane-air, carbon dioxide-air and propane-air. The directed co-flow preserves its axial symmetry at the inlet and its direction varies between +20° and −20°. In addition, the k − ɛ model and model equation of the algebraic non-equal scales are used to investigate effects of the variable density in axisymmetric turbulent jet. Comparative studies are presented in the case of the calculations of the average variables such as the longitudinal velocity, species concentration and the turbulent kinetic energy. The results obtained indicate that the directed co-flow with positive angles enhances considerably the mixing.