University of Guilan Journal of Mathematical Modeling 2345-394X 12 1 2024 03 01 A uniformly convergent computational method for singularly perturbed parabolic partial differential equation with integral boundary condition 157 175 7394 10.22124/jmm.2023.24590.2198 EN Getu Mekonnen Wondimu Mathematics Department, Adama Raya University, Maichew, Ethiopia Gemechis File Duressa Department of Mathematics, Jimma University, Jimma, Ethiopia Mesfin Mekuria Woldaregay Department of Applied Mathematics, Adama Science and Technology University, Adama, Ethiopia Tekle Gemechu Dinka Applied Mathematics, Adama Science and Technology University, Adama, Ethiopia Journal Article 2023 05 24 This paper presents a numerical method for a class of singularly perturbed parabolic partial differential equations with integral boundary conditions (IBC). The solution to the considered problem exhibits pronounced boundary layers on both the left and right sides of the spatial domain. To address this challenging problem, we propose the use of the implicit Euler method for time discretization and a finite difference method on a well-designed piecewise uniform Shishkin mesh for spatial discretization. The integral boundary condition is approximated using Simpson's $\frac{1}{3}$ rule. The presented method demonstrates almost second-order uniform convergence in the discretization of the spatial derivative and first-order convergence in the discretization of the time derivative. To validate the applicability and accuracy of the proposed method, two illustrative examples are employed. The computational results not only accurately reflect the theoretical estimations but also highlight the method's effectiveness in capturing the intricate features of singularly perturbed parabolic partial differential equations with integral boundary conditions. https://jmm.guilan.ac.ir/article_7394_1c073111c73b1a08462b46083684e3e6.pdf