© 2001 by Institute of Mathematics and its Applications
Superconvergent derivative recovery for the intermediate finite element family of the second type
1 Department of Mathematics, Wayne State University, Detroit, MI 48202, USA. Email: zzhang@math.wayne.edu 2 The Institute of Systems Science, Chinese Academy of Sciences, Beijing 100080, People's Republic of China 3 Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
In this work, a recovery technique for the intermediate finite element family of the second type is proposed and analysed on a second-order elliptic model problem. It is shown that when the pollution error is properly controlled, the convergence rate of the recovered gradient is two orders higher than the optimal global rate on an interior subdomain where rectangular meshes of regular type are applied. Some numerical results are provided to confirm the theoretical findings.
Key Words: finite element methods; integral identity; superconvergent recovery; intermediate family