• Media type: E-Article
  • Title: Long-time solutions of scalar hyperbolic reaction equations incorporating relaxation and the Arrhenius combustion nonlinearity
  • Contributor: Leach, J A; Bassom, Andrew P
  • imprint: Oxford University Press (OUP), 2022
  • Published in: IMA Journal of Applied Mathematics
  • Language: English
  • DOI: 10.1093/imamat/hxab047
  • ISSN: 0272-4960; 1464-3634
  • Keywords: Applied Mathematics
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title> <jats:p>We consider an initial-value problem based on a class of scalar nonlinear hyperbolic reaction–diffusion equations of the general form $$\begin{align*} &amp; u_{\tau\tau}+u_{\tau}=u_{{xx}}+\varepsilon (F(u)+F(u)_{\tau} ), \end{align*}$$in which ${x}$ and $\tau $ represent dimensionless distance and time, respectively, and $\varepsilon&amp;gt;0$ is a parameter related to the relaxation time. Furthermore, the reaction function, $F(u)$, is given by the Arrhenius combustion nonlinearity, $$\begin{align*} &amp; F(u)=e^{-{E}/{u}}(1-u), \end{align*}$$in which $E&amp;gt;0$ is a parameter related to the activation energy. The initial data are given by a simple step function with $u({x},0)=1$ for ${x} \le 0$ and $u({x},0)=0$ for ${x}&amp;gt; 0$. The above initial-value problem models, under certain simplifying assumptions, combustion waves in premixed gaseous fuels; here, the variable $u$ represents the non-dimensional temperature. It is established that the large-time structure of the solution to the initial-value problem involves the evolution of a propagating wave front, which is of reaction–diffusion or reaction–relaxation type depending on the values of the problem parameters $E$ and $\varepsilon $.</jats:p>