Generalized Correction Algorithm for the Finite-Difference Diffusion Equations in Askew–Takeda Method

This paper describes a correction algorithm for the finite-difference diffusion equation which increases the coarse mesh accuracy. The equations are transformed to the form of the well-known discretization method for the Askew diffusion equation (Askew’s coarse mesh method). However, the new expressions obtained for the correction coefficients provide a higher accuracy of the finite-difference approximation.