IMA Journal of Numerical Analysis Advance Access published online on August 11, 2009
IMA Journal of Numerical Analysis, doi:10.1093/imanum/drp033
A robust grid equidistribution method for a one-dimensional singularly perturbed semilinear reaction–diffusion problem


Mathematics and Statistics Department, University of Limerick, Limerick, Ireland
Email: naresh.chadha{at}ul.ie
Corresponding author. Email: natalia.kopteva{at}ul.ie
Received on 30 May 2007. Revised on 13 February 2008.
| Abstract |
|---|
The numerical solution of a singularly perturbed semilinear reaction–diffusion two-point boundary-value problem is addressed. The method considered is adaptive movement of a fixed number (N + 1) of mesh points by equidistribution of a monitor function that uses discrete second-order derivatives. We extend the analysis by Kopteva & Stynes (2001, SIAM J. Numer. Anal., 39, 1446–1467) to a new equation and a more intricate monitor function. It is proved that there exists a solution to the fully discrete equidistribution problem, i.e. a mesh exists that equidistributes the discrete monitor function computed from the discrete solution on this mesh. Furthermore, in the case when the boundary-value problem is linear, it is shown that after O(| ln
|/ ln N) iterations of the algorithm, the piecewise linear interpolant of the computed solution achieves second-order accuracy in the maximum norm, uniformly in the diffusion coefficient
2. Numerical experiments are presented that support our theoretical results.
Key Words: grid equidistribution; reaction–diffusion; singular perturbation; adaptive mesh; finite differences; maximum norm