A COMPUTATIONAL METHOD FOR SOLVING SINGULARLY PERTURBED TURNING-POINTPROBLEMS EXHIBITING TWIN BOUNDARY-LAYERS

Singularly perturbed turning point problems (TPPs) for second order or dinary differential equations (DEs) exhibiting twin boundary layers ar e considered. In order to obtain numerical solution of these problems a computational method is suggested in which exponentially fitted diff erence schemes are combined with classical numerical methods. In this method, the given interval (domain of definition of differential equat ion) is divided into four subintervals and we solve the differential e quation in each interval and combine the solution. The implementation of the method on parallel architectures is mentioned. Error estimates are derived and numerical examples are given. (C) 1998 Elsevier Scienc e Inc. All rights reserved.