TY - JOUR T1 - The Gradient Superconvergence of Bilinear Finite Volume Element for Elliptic Problems JO - Numerical Mathematics: Theory, Methods and Applications VL - 4 SP - 579 EP - 594 PY - 2016 DA - 2016/09 SN - 9 DO - http://doi.org/10.4208/nmtma.2016.m1515 UR - https://global-sci.org/intro/article_detail/nmtma/12390.html KW - AB -

We study the gradient superconvergence of bilinear finite volume element (FVE) solving the elliptic problems. First, a superclose weak estimate is established for the bilinear form of the FVE method. Then, we prove that the gradient approximation of the FVE solution has the superconvergence property:

image.png

where image.png denotes the average gradient on elements containing point $P$ and $S$ is the set of optimal stress points composed of the mesh points, the midpoints of edges and the centers of elements.