Journal of Chemical Physics
Autocatalytic chemical fronts of the chlorite-tetrathionate ~CT! reaction become buoyantly unstable when they travel downwards in the gravity field because they imply an unfavorable density stratification of heavier products on top of lighter reactants. When such a density fingering instability occurs in extended Hele-Shaw cells, several fingers appear at onset which can be characterized by dispersion relations giving the growth rate of the perturbations as a function of their wave number. We analyze here theoretically such dispersion curves comparing the results for various models obtained by coupling Darcy’s law or Brinkman’s equation to either a one-variable reaction-diffusion model for the CT reaction or an eikonal equation. Our theoretical results are compared to recent experimental data.
dispersion, physics, convective, Hale-Shaw cells, chemical physics
Desiderio A. Vasquez and A. DeWitt (2004).
Dispersion Relations for the Convective Instability of an Acidity Front in Hele-Shaw Cells. Journal of Chemical Physics.121 (2), 935-941.