Numerical simulation of gas flow field in supersonic swirler

To interrogate the effects of the swirling inlet on the supersonic nozzle flow and its characteristics, a set of front-mounted supersonic swirlers were designed on the basis of the existing swirler by simplifying the model. A three-dimensional geometric model of the swirler was established and integrated with a supersonic nozzle. The flow field of the whole system was then numerically simulated by using a computational fluid dynamics （CFD） software Fluent, and the realizable k-ε turbulence model. It was shown that when keeping the inlet total pressure constant, the maximum tangential velocity rate of the flow generated in the swirler increased with the decrease of intake passages. However, the nozzle flow clearly exhibited the characteristic of spiral vortexes. As the angular momentum decreased at the expense of the axial momentum, the increase of the tangential velocity led to the decrease of the averaged axial velocity at the nozzle exit plane. It was also discovered that when the inlet total pressure increased, the distribution of gas velocity and temperature in the converging section was close. Meanwhile, the gas velocity and Mach number increased as the static temperature decreased along the nozzle diverging section. In addition, the tangential velocity displayed almost an identical distribution across the radial direction at the nozzle exit plane.