Fully computable bounds for a staggered discontinuous Galerkin method for the Stokes equations

We first propose a guaranteed upper bound for an arbitrary order staggered discontinuous Galerkin (staggered DG) method for the Stokes equations with the use of the global inf–sup constant. Equilibrated stress reconstruction and velocity reconstruction are the main ingredients in the construction of the error estimator. Next, to improve the error estimation and to overcome the difficulties caused by the calculation of the global inf–sup constant, a refined error control relying on local inf–sup constants is also developed. Some minimization techniques and an explicit method are then established to facilitate the construction of the refined error control. Finally, some benchmark examples are tested to compare the performances of the proposed error estimators.