Effects of the swirler on the performance of an advanced vortex combustor

Abstract

Trapped vortex combustors have garnered significant interest due to the cavity vortex's insensitivity to flow disturbances. Swirling combustion is also highly desirable due to its excellent mixing performance. This study explores the potential of combining vortex combustors with swirling combustion under reacting conditions. Steady-state Reynolds-averaged Navier–Stokes equations are solved through three-dimensional numerical simulations. The results demonstrate a significant improvement in combustion efficiency, from 55% in original vortex combustor to over 99% in swirling vortex combustor, and fuel–air mixing effectiveness. The spatial spiraled vortex structure forms in the cavity and behind the blunt body when the swirler is used. The position of the blunt body influences the shape of the cavity vortex, with a round vortex structure forming when the cavity length to the total combustion chamber length ratio is around 0.2. When the radius of the blunt body to the radius of the combustion chamber, varying from 0.2 to 0.7, is 0.6, two main recirculation zones can be created in the model. Increasing the swirling number results in a larger recirculation zone in the cavity, with an elongated recirculation area appearing behind the blunt body at a blade installation angle of 60°, corresponding to the swirling number is 1.251. However, an excessively high swirling number leads to uneven pressure distribution in the outlet. These findings provide novel insights for advanced vortex combustor research and optimization.