Superconvergence of the Bernadi-Raugel Mixed Finite Element Approximation for the Three-Dimensional Stokes Problem

Superconvergence of a mixed finite element approximation for the three-dimensional Stokes problem is presented.By using the Bernadi-Raugel mixed finite elements which satisfies the Babuska-Brezzi condition a basic error is gained.Considering the problem on the piecewise uniform cuboid elements in the three-dimensional space,the convergence rate of the solution can be increased an order by using the interpolation and Bramble-Hibert lemma.