Matrix-equation-based strategies for convection–diffusion equations

We are interested in the numerical solution of nonsymmetric linear systems arising from the discretization of convection–diffusion partial differential equations with separable coefficients, dominant convection and rectangular or parallelepipedal domain. Preconditioners based on the matrix equation formulation of the problem are proposed, which naturally approximate the original discretized problem. For the considered setting, we show that the explicit solution of the matrix equation can effectively replace the linear system solution. Numerical experiments with data stemming from two and three dimensional problems are reported, illustrating the potential of the proposed methodology.