Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T03:34:24.792Z Has data issue: false hasContentIssue false

Blow-up in a fourth-order semilinear parabolic equation from explosion-convection theory

Published online by Cambridge University Press:  26 January 2004

V. A. GALAKTIONOV
Affiliation:
Department of Mathematical Sciences, University of Bath, Bath BA2 7AY, UK Keldysh Institute of Applied Mathematics, Miusskaya Sq. 4, 125047 Moscow, Russia email: [email protected]
J. F. WILLIAMS
Affiliation:
Department of Mathematical Sciences, University of Bath, Bath BA2 7AY, UK email: [email protected]

Abstract

We describe various blow-up patterns for the fourth-order one-dimensional semilinear parabolic equation \[ u_t = - u_{xxxx} + \b [(u_x)^3]_x + e^{u} \] with a parameter $\b \ge 0$, which is a model equation from explosion-convection theory. Unlike the classical Frank-Kamenetskii equation $u_t=u_{xx} +e^u$ (a solid fuel model), by using analytical and numerical evidence, we show that the generic blow-up in this fourth-order problem is described by a similarity solution $u_*(x,t) = -\ln(T\,{-}\,t) \,{+}\, f_1(x/(T\,{-}\,t)^{1/4})(T>0$ is the blow-up time), with a non-trivial profile $f_1 \not \equiv 0$. Numerical solution of the PDE shows convergence to the self-similar solution with the profile $f_1$ from a wide variety of initial data. We also construct a countable subset of other, not self-similar, blow-up patterns by using a spectral analysis of an associated linearized operator and matching with similarity solutions of a first-order Hamilton–Jacobi equation.

Type
Papers
Copyright
2003 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)