Analysis of vortex combustion flow in a chamber of guide ring coupling with swirl flow

To investigate the impact of different vortex structure on the combustion stability in a chamber, this paper evaluates the performance of a vortex combustion chamber coupled with a swirler and a guide ring. The simulated cases include different guide ring angles of 95 degrees, 105 degrees, 115 degrees, 125 degrees and 135 degrees, in addition to a control case without coupling the guide ring. The distributions of velocity, vorticity, temperature, outlet temperature distribution factor (OTDF), reaction rate, turbulent kinetic energy (k), synergy angle (beta), and NO emission are numerically analyzed. Results show that the coupling of the swirler and guide ring changes the vortex structure and significantly influences the chamber performance. The increase of the guide ring angles (alpha) enhances the interaction between the swirl flow and the direct jet, which intensifies heat and mass transfer, as well as turbulence. The application of the guide ring induces external entrainment of the jet, leading to the formation of a large central recirculation zone compared to that without a guide ring. With increasing the alpha from 95 degrees to 135 degrees, both average outlet velocity and tangential velocity (V-t) at the coaxial line position decrease, while the flame length decreases by 286 mm. And the OTDF variation among all cases is less than 0.065. The beta of the central section decreases from 76.18 degrees to 70.17 degrees. Furthermore, combustion chamber without the guide ring exhibits higher temperature and OTDF.