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Front fingering and complex dynamics driven by the interaction of buoyancy and diffusive instabilities
J D'Hernoncourt1, J H Merkin, A De Wit
1Nonlinear Physical Chemistry Unit and Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, 1050 Brussels, Belgium.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 13, 2007
Summary
Traveling fronts exhibit complex instabilities due to diffusion and buoyancy. Their interaction can trigger convection and spatiotemporal chaos, even in stable conditions, offering new insights into front dynamics.
Area of Science:
- Physics
- Fluid Dynamics
- Chemical Engineering
Background:
- Traveling fronts can destabilize via diffusive or buoyancy-driven Rayleigh-Taylor mechanisms.
- Differential diffusion rates or unfavorable density jumps cause these instabilities.
Purpose of the Study:
- To analyze the interaction between diffusive and buoyancy instabilities in traveling fronts.
- To investigate how this interplay affects front stability and dynamics.
Main Methods:
- Theoretical analysis of a simple model system.
- Linear stability analysis.
- Nonlinear simulations.
Main Results:
- The interplay between diffusive and buoyancy instabilities significantly alters front stability compared to individual mechanisms.
- Differential diffusion can induce convection around statically stable fronts.
- Cooperation between buoyancy and diffusion can lead to spatiotemporal chaos.
Conclusions:
- The combined effects of diffusive and buoyancy instabilities create complex front behaviors not predicted by studying them in isolation.
- This research predicts novel instability scenarios and chaotic dynamics in traveling fronts.
- Experimental validation of these predictions is feasible under suggested conditions.
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