Related Experiment Videos
Excitable media in a chaotic flow
1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, United Kingdom.
Physical Review Letters
|September 5, 2001
Summary
Localized perturbations in excitable media show global excitation under stirring. However, slow stirring disrupts this coherence, as explained by a simple model of flow effects on excitable dynamics.
Area of Science:
- Complex systems
- Fluid dynamics
- Nonlinear dynamics
Background:
- Excitable media exhibit wave propagation phenomena.
- Chaotic advection can significantly alter transport properties.
- Understanding flow-medium interactions is crucial for predicting system behavior.
Purpose of the Study:
- Investigate the response of an excitable medium to localized perturbations under chaotic advection.
- Determine the critical stirring rate for coherent global excitation.
- Model the influence of flow on excitable dynamics.
Main Methods:
- Simulations of localized perturbations in a stirred excitable medium.
- Analysis of excitation coherence at varying stirring rates.
- Development of a reduced model for flow-excitable dynamics.
Main Results:
- A critical stirring rate was identified below which global excitation is coherent.
- For very slow stirring, excitation coherence is lost.
- A steady excited filament state was found in the reduced model, explaining the observed behavior.
Conclusions:
- Chaotic advection critically influences the global response of excitable media.
- The transition from coherent to incoherent excitation is governed by stirring rate.
- A simple model successfully captures the essential dynamics of flow-perturbed excitable systems.