Summary: A new stabilized finite element method for Stokes problem is presented. The method is obtained by modification of the mixed variational equation by using local polynomial pressure projections. Our stabilization approach is motivated by the inherent inconsistency of equal-order approximations for Stokes equations, which leads to an unstable mixed finite element method. Application of pressure projections in conjunction with minimization of the pressure-velocity mismatch eliminates this inconsistency and leads to a stable variational formulation.
Unlike other stabilization methods, the present approach does not require specification of a stabilization parameter or calculation of higher-order derivatives, and always leads to a symmetric linear system. The new method can be implemented at the element level, and for affine families of finite elements on simplicial grids it reduces to a simple modification of weak continuity equation. Numerical results are presented for a variety of equal-order continuous velocity and pressure elements in two and three dimensions.