Analytic-numerical investigation of combustion in a nonlinear medium

Sufficient conditions of the onset of the blow-up mode for the parabolic equation with double nonlinearity that describes the combustion process in a nonlinear medium are analyzed. A sufficient condition for the initial function under which the time of the solution blow-up of the corresponding initial-boundary value problem for this equation is finite is obtained. An analytical upper bound on the solution existence time is derived. This a priori bound on the solution blow-up time is used for the numerical refinement of the blow-up process. It is shown that the numerical diagnostics of the solution blow-up makes it possible to obtained a better estimate of the solution blow-up time and detect the fact of local blow-up with respect to the spatial variable.