Numerical simulations of flame patterns supported by a spinning burner

• Published in: Proceedings of the Combustion Institute Vol. 32; no. 1; pp. 1209 - 1217
• Main Authors: Hossain, Kishwar N., Jackson, Thomas L., Buckmaster, John D.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 2009
• Subjects: Diffusion flames; Flame patterns; Instabilities; Laminar flames; Three-dimensional simulations; Laminar flames; Diffusion flames; Instabilities; Three-dimensional simulations; Flame patterns
• ISSN: 1540-7489; 1873-2704
• DOI: 10.1016/j.proci.2008.06.015

Non-uniform methane diffusion flames, formed from a porous plug burner spinning in quiescent air, are investigated numerically in a three-dimensional context. Flames are simulated for Damköhler numbers on the upper branch of the S-shaped response curve close to the extinction point. Multi-dimensional instabilities appear in the form of holes and spirals at these near extinction Damköhler numbers, as observed in experimental studies of flames sustained by a rotating porous burner [V. Nayagam, F.A. Williams, Pattern Formation in Diffusion Flames Embedded in Von Karman Swirling Flows, NASA/CP 2001-21082; V. Nayagam, F.A. Williams, Pattern Formation in Diffusion Flames Embedded in Von Karman Swirling Flows, NASA/CR 2006-214057]. Simulation results from the constant density and constant viscosity model suggest that the non-uniform flames are a result of thermo-diffusional instabilities and are a function of the Damköhler number. The simulated flame holes have stationary edges while the single and double spirals have edges that rotate about the axis of the burner. It is found that boundary conditions such as the mixture strength and the injection velocity affect the range of Damköhler numbers within which the system is unstable.