title: Convection in stable and unstable fronts.
abstract: Density gradients across a reaction front can lead to convective fluid motion. Stable fronts require a heavier fluid on top of a lighter one to generate convective fluid motion. On the other hand, unstable fronts can be stabilized with an opposing density gradient, where the lighter fluid is on top. In this case, we can have a stable flat front without convection or a steady convective front of a given wavelength near the onset of convection. The fronts are described with the Kuramoto-Sivashinsky equation coupled to hydrodynamics governed by Darcy's law. We obtain a dispersion relation between growth rates and perturbation wave numbers in the presence of a density discontinuity accross the front. We also analyze the effects of this density change in the transition to chaos.
authors.affiliation: Department of Physics, Indiana University Purdue University Fort Wayne, Fort Wayne, Indiana 46805, USA.
authors.forename: Drew
authors.initials: D
authors.lastname: Elliott
authors.forename: Desiderio A
authors.initials: DA
authors.lastname: Vasquez