Vortex Dynamics and Suppression of Chemical Turbulence in Autocatalytic Reaction-Diffusion Systems

Florida State University, Tallahassee FL

Investigators

Abstract

In this project funded by the Chemistry Division (Chemical Structure, Dynamics and Mechanisms A), Professor Oliver Steinbock (Florida State University) is studying how seemingly simple chemical reactions can form complex life-like patterns. Chemical reactions in a laboratory container can produce macroscopic patterns that include rotating spirals that appear visually as striking blue bands on a red background. Closely related spirals exist as electrical phenomena also in the human heart where they cause life-threatening conditions and are among the leading causes of death in the US. Professor Steinbock and his students will investigate the behavior of these spiral waves in thick layers that model the heart focusing on specific questions including the effect of height variations. They will also study the pinning of these spirals to inert areas that correspond to anatomical features and scar tissue formed after heart attacks. This project uses the autocatalytic Belousov-Zhabotinsky (BZ) reaction and numerical simulations of reaction-diffusion models to investigate self-propagating concentration waves. In three dimensions, these nonlinear waves can take the form of vortices that rotate around one-dimensional phase singularities called filaments. Filament motion can generate a form of spatio-temporal chaos that shares many dynamical similarities with ventricular fibrillation in the human heart. The effect of non-reactive heterogeneities on periodic and chaotic vortices will be investigated with a focus on the defect-mediated suppression of turbulent states as well as the translational motion of vortices along step edges. Another component is the study of vortex pinning in higher dimensional networks. The outreach program includes the dissemination of key results and pertinent background information to laymen and teachers using YouTube videos and other internet-based resources.