Visualization of flow structures in an isothermal swirling flow in a confined domain

A computational study of flow structure have been carried in the current study. The swirling flow involves much more complexity than the non-swirl flow due to higher probabilities of instabilities, asymmetric vortex core, precessing vortex core, Internal recirculation zone (IRZ), vortex breakdown, and other coherent flow structures. This brings attention to study and analyze these effects by visualizing the flow with such a method so that each type of structure can be more understandable than previous studies. We visualized the swirling flow in a confined domain by simulating the transient isothermal flow using RANS modeling on Ansys fluent platform. The results reveal that the patterns of flow structures are in a vast range as the vortex core and IRZ keeps on switching their state from symmetric and steady to asymmetric and transient. These precarious states are found to be dependent on Reynolds number, swirl strength, method of generating swirl and domain type.