IN fluent,there is a under-ralexation-factor,like some expert para,but where can i find the factor in CFX?

The same. Under Expert parameters. Take a look in the online manual.

CFX does not use under-relaxation parameters like Fluent or other segregated solvers do. The timestep provides the necessary relaxation in a physical manner by increasing or decreasing the influence of the transient term.

See the help on monitoring and improving convergence for more information.

-Robin

IN CFX,i think the expert parameter means that under-relaxt-factor,before u told me! If so,the expert parameter seems more powerful than that under-relaxt-factor,i must learn them more,

thanks a lot!

Are u sure of this? It seems the Relaxation Parameters under Expert Parameters are those typical parameters. I never paid attention on these, thought timestep is the only thing. But now, I know more.

The necessity to change these is different because the solvers is completely different. Unless you are specifically directed to change one of these parameters by support, leave them alone.

-Robin