Solving Second-order Elliptic Problem In Domain With Curves Boundaries By Multilevel Adaptive Rectangular Meshes With Hanging Nodes

In this paper,we solve second-order elliptic problem in domains with curved boundaries by multilevel adapative grids.we use bilinear rectangular element with hanging nodes . ususlly, the convergence order is O(h^1/2) .but if we apply the multilevel adaptive methods. the convergence order is O(h). this rusult is the same convergence order as the convex polygon with the precise rectangular meshs. In this paper ,we define the hanging nodes ,we discuss the error estimate inΩ_h^l andΩ\Ω_h^l.for examine the result,we give the numerical example.