Flow regimes and vortex characteristics in a swirling T-jets reactor

Flow regimes and vortex characteristics in a swirling T-jets reactor are studied by employing particle image velocimetry (PIV) and proper orthogonal decomposition (POD) techniques at 50 < Re < 460 (where Re is Reynolds number). Regarding the case of Re > 155, the symmetry of the flow structure within the reactor is disrupted, leading to periodic tilting of vortex rings and the formation of an asymmetric oscillation flow. Statistical characteristics of the flow field indicate that turbulent kinetic energy along the central axis of the chamber is relatively low in the asymmetric oscillation flow. Meanwhile, the regions of high turbulent kinetic energy are located near the shear layers both inside and outside the vortex rings, and around the stagnation point at the top of the chamber. Furthermore, a positive correlation between turbulent kinetic energy and the increase of Re. Analysis results derived from POD have identified the large-scale spatial vortex structures that dominate the asymmetric oscillation flow.