Rayleigh-Taylor Unstable Flames: Thick and Thin

Models for the behavior of Rayleigh-Taylor unstable flames typically treat the flame structure as infinitely thin, laminar-like, or turbulently thickened. In this talk, we report the analysis of a large parameter study of direct numerical simulations (DNS) of Rayleigh-Taylor unstable flames and show that none of these simplified models captures their beautifully complex structure. We show that the steepness of the reaction rate and the Prandtl number, parameters that are typically neglected in models, do affect the structure and speed of the flame in significant ways.