Numerical Study of Turbulent Flow in a Tangentially Injected Swirl Generator

The swirl effects in inert and reacting flow systems have been studied for many years. Some processes have appreciated the presence of swirl while some have entitled to curtail the swirl. The swirl intensity is an important parameter in characterizing flows with swirl. In this study, the turbulent flow in a tangentially injected swirl generator was analyzed using commercial CFD software Fluent. The Reynolds numbers considered were 12,500, 15,300, and 30,600 for a fixed ratio of tangential to total momentum flux of 7.84. At Reynolds number 12,500, several cases with various injector configuration and momentum flux ratio were also studied. The numerical results were validated with available experimental data. The results showed that the flow in the generator can be classified into two regions, core and annulus. Reversed flow region was observed in all these cases. The swirl intensity was found to decay exponentially along the axial lengths. The simulations also showed that the swirl intensity was significantly affected by the momentum flux ratio and the Reynolds number.