NONUNIFORM GRID ACCURACY TEST APPLIED TO THE NATURAL-CONVECTION FLOW WITHIN A POROUS MEDIUM CAVITY

Abstract

Abstract The accuracy of numerical results obtained by using nonuniform grid distributions is strongly affected by the size of the grid spacing. The present work focuses on a detailed procedure for the accuracy tests of the numerical results obtained by using nonuniform grid distributions. It is shown that the degree of nonuniformity of a certain grid distribution with a fixed number of grid lines also has a strong effect on the numerical results. For a fixed number of grid lines there is only one optimum nonuniform grid distribution for each physical case. Furthermore, an accurate nonuniform grid for a physical situation with steep gradients presents a very low efficiency in terms of CPU time when used for simulating cases with smaller gradients.