One more time Robin!, I got a couple of questions to you: 1)What do you mean when you say:"... An error correction is solved on each of the coarser grids and passed back up to the finer grids to improve the solution..", I understood like with every iteration the error is reduced until it reach the tolerance value..., I´m wrong?.Where this error correction come from?.

2)What is the diference between time step and iteration?.

Sorry if I made a lot of stupid questions but I finally found someone who can explain to me this kind of things in a very simple way !

Take Care,

Carola

Hi Carola,

The error correction is just a detail of the additive corrective multigrid method and occurs within a single iteration/timestep.

Iteration and timestep are often used interchangably. CFX-5 and CFX-TASCflow include transient terms in the equations and each "iteration" of the solver in a steady state run is also a "timestep". If you run a transient simulation, a single timestep may include multiple iterations, usually referred to a inner coefficient loops.

Hope this helps.

Regards, Robin