Dear Mr. or Mrs.:

I do read parts of FLUENT USER GUIDE which is relevant to AMG and FAS(coupled solver) again and again. But I alway can't understand these two numerical technology completely, because my mother language is not English. Could you explain AMG and FAS in brief, especilly how to use them?

Thank you very much. Sincerely, Harry.

(1). Don't worry about it. (2). If your problem is converging, then these methods "could" speed up the convergence through multi-grid approach.(if you are very lucky, and in most cases it will have negative impact on convergence.) (3). For simple diffusion problems, it is useful to cut down the computing time. Otherwise, don't touch it.