Numerical approximation of convection–diffusion equations in a channel using boundary layer elements

Our aim in this article is to show how one can improve the numerical solution of singularly perturbed problems involving boundary layers. By incorporating the structures of boundary layers into finite element spaces, when this structure is available, we can improve the accuracy of approximate solutions and this results in significant simplifications. In this article we discuss singularly perturbed convection–diffusion equations in a channel producing ordinary boundary layers.