Theory of ignition of a reactive solid by constant energy flux

A formula for the ignition time, that Bradley obtained empirically, is derived analytically by a rigorous asymptotic analysis of the limit of large activation energy. Two terms in the expansión must be retained. The second term reveáis the existence—just prior to ignition—of a reactive-diflfusive zone at the surface of the solid and a transient-diffusive zone in the interior. The analysis also exhibits a universal correction factor for Bradley's formula, of order unit