A METHOD FOR PREDICTING AND MINIMIZING NUMERICAL DIFFUSION

Abstract

Finite-difference numerical techniques based on control volumes provide the most commonly applied method for solution of heat and mass transfer problems. These first-order solutions are prone to substantial inaccuracy introduced by numerical diffusion effects, From a Lagrangian viewpoint, the inaccuracy of interpolation in space and time creates this diffusion. Here, Taylor series expansions for streamwise and cross-stream interpolation processes give numerical diffusion coefficients. These simple coefficients can be used to adjust physical diffusion coefficients, providing second-order accuracy for convection in control volume solutions. The diffusion correction functions derived here are particularly useful for transient solutions.