68th Annual Meeting of the APS Division of Fluid Dynamics (November 22, 2015 — November 24, 2015)

V0079: Structure and Dynamics of a Deflagrated Flame Evolution

Authors

• Jessica Chambers, Propulsion & Energy Research Lab - University of Central Florida
• Michelle Otero, Propulsion & Energy Research Lab - University of Central Florida
• Kareem Ahmed, Propulsion & Energy Research Lab - University of Central Florida
• Joseph McGarry, Propulsion & Energy Research Lab - University of Central Florida

DOI: https://doi.org/10.1103/APS.DFD.2015.GFM.V0079

Flame acceleration plays a critical role for supersonic detonation combustion.  The flame evolves from laminar (kinetics driven) to turbulent (fluid dynamics driven). Turbulence augments the flame through flame wrinkling and enhanced heat-mass transport. The result is controlled flame explosions. The video features the evolution dynamics of a deflagrated flame from laminar to turbulent. We applied a unique Lagrangian flame tracking technique that captures the flame front evolution dynamics. The technique uses high-speed Schlieren imaging at 90,000FPS. This technique endows the fundamental understanding and observation of the flame structural dynamics and evolution. Hydrogen and Methane flames are explored showing striking differences in both explosions. The laminar flame experiences flame-flow instabilities that results in flame wrinkling. Through boundary layer interaction and pressure gradients due to flow expansion, the flame transitions in to a tulip flame structure that then transforms in to a turbulent flame.