A STUDY ON CONVERGENCE CRITERIA FOR A SIMPLE-BASED FINITE-VOLUME ALGORITHM

Two commonly used quantities for deciding numerical iteration converge nce of elliptic and parabolic flow fields are assessed. Three 2-D test case problems, which are representative of many problems of momentum and/or heat transport, are used. The numerical model employed is the p ressure-based finite-volume algorithm SIMPLE to solve the steady, inco mpressible-flow Navier-Stokes equations in full elliptic form. Conside rable insight is gained by comparing the variation of the two quantiti es with the true mean relative error for the velocity components, the local mass imbalance, and the temperature. It is concluded that, excep t when using low underrelaxation factors, use of the maximum local val ue of the relative change, over two consecutive iterations, of the dep endent variable is somewhat more appealing than the nondimensionalized sum of the local residual magnitudes.