Isothermal flame balls

Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Jul;66(1 Pt 2):016207. doi: 10.1103/PhysRevE.66.016207. Epub 2002 Jul 15.

Abstract

The existence of steady, spherically symmetric wave fronts ("isothermal flame balls") in chemical reaction systems exhibiting autocatalysis is demonstrated. Such solutions require relatively high kinetic orders p with respect to the autocatalytic species, with p>5, but occur even with equal diffusion coefficients. The flame balls are unstable, but have relevance as they indicate the minimum size for a perturbation to initiate a propagating front. A flame ball radius R(b) is identified and the dependence of this quantity on the autocatalytic order is determined. This shows R(b) tending to infinity as p-->5(+) and as p--> infinity, with a minimum for p approximately 6.71. Numerical computations are confirmed by asymptotic analysis appropriate for p-->5(+) and for systems with p large.