Numerical investigation on mixing of heated confined swirling coaxial jets with blockage

A coaxial jet that has one application in gas turbine combustion chambers where there is a requirement for very good mixing of air and fuel for complete and stable combustion. A study has been carried out to improve the mixing of annular and central jets in the confined space of the combustor. The combustor model is used with two confined coaxial air-swirling jets under non-combustion conditions. The influence of a heated central jet and the effect of blockage at different locations in confined spaces on mixing has been studied. To understand mixing in jets in confinement, the center line axial velocity profile and streamlines have been presented at different locations. The computational results are obtained using commercial CFD software, ANSYS FLUENT 18.0, with a standard k–ω turbulence model. After validation with the existing literature, parametric studies have been carried out with co-swirl and counter-swirl conditions of annular and central jets at different blockage locations in confinement. The results show a good understanding of the mixing process of two jets in confinement.