An Investigation of Internal Flow Field and Swirling Jet Exiting a Cyclone Vortex Combustion Chamber

Tangential injection of oxidizer near the nozzle attached to a cyclone vortex chamber gives rise to a distinct vortical-helical motion over the entire length of the Cyclone Vortex Combustion Chamber. Flow reverses its direction at the head wall and forms a core consisting of vortex filaments, and travels down the chamber before exiting through the nozzle. Primary advantages of combustion in the vortex chamber are prolonged fuel residence time, increased fuel/oxidizer mixing length and thermal shielding of chamber walls. Preliminary flow visualization results showed bifurcation of flow in the vortex chamber and unique swirling jet at the exit, and reversed flow under certain conditions. Both the axial flow and swirl of jet showed strong dependence on the injector geometry, chamber aspect ratio, state of boundary layer on nozzle walls, and inlet mass flow rate. Results of the connectivity between the internal and external flow, characteristics of jet, including transport of turbulent kinetic energy, and flow instabilities are presented and discussed.