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Flame Acceleration Associated with the Darrieus-Landau Instability
Applied Math| Speaker: | Ralph C. Aldredge, Dept. of Mechanical and Aeronautical Engineering |
| Location: | 693 Kerr |
| Start time: | Fri, Nov 2 2001, 4:10PM |
Flame acceleration associated with the Darrieus-Landau hydrodynamic instability is investigated computationally using an analytical model of premixed-flame st ructure valid in the limit of large-chemical-activation energies and weak flame stretch. A level-set formulation is used to track the evolution of the premixe d flame and the Euler equations are used to describe the flow field. Coupling b etween the flame and flow-field dynamics resulting from order-unity gas expansi on within the flame is found to result in growth of the average radius of outwa rdly propagating flames in proportion with the 3/2 power of time, consistent wi th experiment. Influences of the flame thickness, relative to the length scale of the hydrodynamic flow, and of the density ratio across the flame on the crit ical Reynolds numbers associated with the onset of wrinkled-flame propagation a nd self-similar acceleration are predicted also.
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