A Layer Adaptive B-Spline Collocation Method for Singularly Perturbed One-Dimensional Parabolic Problem with a Boundary Turning Point

In this article, we develop a parameter uniform numerical method for a class of singularly perturbed parabolic equations with a multiple boundary turning point on a rectangular domain. The coefficient of the first derivative with respect to x is given by the formula a(0)(x, t)x(p), where a(0)(x, t) >= alpha > 0 and the parameter p is an element of [1, infinity) takes the arbitrary value. For small values of the parameter e, the solution of this particular class of problem exhibits the parabolic boundary layer in a neighborhood of the boundary x = 0 of the domain. We use the implicit Euler method to discretize the temporal variable on uniform mesh and a B-spline collocation method defined on piecewise uniform Shishkin mesh to discretize the spatial variable. Asymptotic bounds for the derivatives of the solution are established by decomposing the solution into smooth and singular component. These bounds are applied in the convergence analysis of the proposed scheme on Shishkin mesh. The resulting method is boundary layer resolving and has been shown almost second-order accurate in space and first-order accurate in time. It is also shown that the proposed method is uniformly convergent with respect to the singular perturbation parameter e. Some numerical results are given to confirm the predicted theory and comparison of numerical results made with a scheme consisting of a standard upwind finite difference operator on a piecewise uniform Shishkin mesh. (C) 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 27: 1143-1164, 2011