Superconvergent Finite Element Postprocessing for Eigenvalue Problems with Nonlocal Boundary Conditions

摘要

We present a postprocessing technique applied to a class of eigenvalue problems on a convex polygonal domain Ω in the plane, with nonlocal Dirichlet or Neumann boundary conditions on Γ{sub}1{is contained in}{partial deriv}Ω. Such kind of problems arise for example from magnetic field computations in electric machines. The postprocessing strategy accelerates the convergence rate for the approximate eigenpair. By introducing suitable finite element space as well as solving a simple additional problem, we obtain good approximations on a coarse mesh. Numerical results illustrate the efficiency of the proposed method.