A parameter-free stabilized finite element method for scalar advection-diffusion problems

We formulate and study numerically a new, parameter-free stabilized finite element method for advectiondiffusion problems. Using properties of compatible finite element spaces we establish connection between nodal diffusive fluxes and one-dimensional diffusion equations on the edges of the mesh. To define the stabilized method we extend this relationship to the advection-diffusion case by solving simplified one-dimensional versions of the governing equations on the edges. Then we use H(curl)-conforming edge elements to expand the resulting edge fluxes into an exponentially fitted flux field inside each element. Substitution of the nodal flux by this new flux completes the formulation of the method. Utilization of edge elements to define the numerical flux and the lack of stabilization parameters differentiate our approach from other stabilized methods. Numerical studies with advection-diffusion test problems on a range of structured and unstructured grids confirm the excellent stability and robustness of the new method. MSC: AMS Mathematics Subject Classification (2000) numbers: 65N30, 65N12