%0 Journal Article %T High Order Compact Difference Scheme and Multigrid Method for 2D Elliptic Problems with Variable Coefficients and Interior/Boundary Layers on Nonuniform Grids %A Bin Lan %A Yongbin Ge %A Yan Wang %A Yong Zhan %J Journal of Applied Mathematics and Physics %P 509-523 %@ 2327-4379 %D 2015 %I Scientific Research Publishing %R 10.4236/jamp.2015.35063 %X In this paper, a high order compact difference scheme and a multigrid method are proposed for solving two-dimensional (2D) elliptic problems with variable coefficients and interior/boundary layers on nonuniform grids. Firstly, the original equation is transformed from the physical domain (with a nonuniform mesh) to the computational domain (with a uniform mesh) by using a coordinate transformation. Then, a fourth order compact difference scheme is proposed to solve the transformed elliptic equation on uniform girds. After that, a multigrid method is employed to solve the linear algebraic system arising from the difference equation. At last, the numerical experiments on some elliptic problems with interior/boundary layers are conducted to show high accuracy and high efficiency of the present method. %K Elliptic Equation %K Coordinate Transformation %K High Order Compact Difference Scheme %K Multigrid Method %K Interior/Boundary Layer %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=56416