Dynamic subgrid modelling for time dependent convection-diffusion-reaction equations with fractal solutions

A dynamic scale similarity model is proposed. The subgrid model is tested for model problems related to time dependent non-linear convection-diffusion-reaction systems with fractal solutions. The error of an approximate solution with subgrid model on a scale h is typically smaller than that of a solution without subgrid model on the scale h/2. We also consider the problem of a posteriori error estimation for fractal solutions, splitting the total computational error into a numerical error, related to the discretization of the continuous equations, and a modelling error, taking into account the quality of the subgrid model. Copyright (C) 2002 John Wiley Sons, Ltd.