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Article Dans Une Revue Physical Review E : Statistical, Nonlinear, and Soft Matter Physics Année : 2001

Front propagation in laminar flows

Résumé

The problem of front propagation in flowing media is addressed for laminar velocity fields in two dimensions. Three representative cases are discussed: stationary cellular flow, stationary shear flow, and percolating flow. Production terms of Fisher-Kolmogorov-Petrovskii-Piskunov type and of Arrhenius type are considered under the assumption of no feedback of the concentration on the velocity. Numerical simulations of advection-reaction-diffusion equations have been performed by an algorithm based on discrete-time maps. The results show a generic enhancement of the speed of front propagation by the underlying flow. For small molecular diffusivity, the front speed Vf depends on the typical flow velocity U as a power law with an exponent depending on the topological properties of the flow, and on the ratio of reactive and advective time scales. For open-streamline flows we find always Vf?U, whereas for cellular flows we observe Vf?U1/4 for fast advection and Vf?U3/4 for slow advection.
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Dates et versions

hal-00016496 , version 1 (05-01-2006)

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Mathieu Abel, Antonio Celani, D. Vergni, D. Vulpiani. Front propagation in laminar flows. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2001, 64, pp.046307. ⟨10.1103/PhysRevE.64.046307101103/PhysRevE.64.046307⟩. ⟨hal-00016496⟩
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