PERSPECTIVE - A METHOD FOR UNIFORM REPORTING OF GRID REFINEMENT STUDIES

This paper proposes the use of a Grid Convergence Index (GCI) for the uniform reporting of grid refinement studies in Computational Fluid Dy namics. The method provides an objective asymptotic approach to quanti fication of uncertainty of grid convergence. The basic idea is to appr oximately relate the results from any grid refinement test to the expe cted results from a grid doubling using a second-order method. The GCI is based upon a grid refinement error estimator derived from the theo ry of generalized Richardson Extrapolation. It is recommended for use whether or not Richardson Extrapolation is actually used to improve th e accuracy, and in some cases even if the conditions for the theory do not strictly hold. A different form of the GCI applies to reporting c oarse grid solutions when the GCI is evaluated from a ''nearby'' probl em. The simple formulas may be applied a posteriori by editors and rev iewers, even if authors are reluctant to do so.