Mixed finite element methods for the Oseen problem

Abstract

The aim of this paper is to develop and analyze mixed finite element methods for the Oseen problem using the tensor gradient of velocity as a new unknown. We prove that the new variational formulation and the corresponding Galerkin scheme are well-posed. We also provide optimal order error estimates for the velocity, the pressure, and the gradient of velocity when each row of the velocity gradient is approximated by Raviart–Thomas elements and the velocity and the pressure are approximated by discontinuous piecewise polynomials.