iteration
 

if i have one phase flow 500 iteration 7 min
if i have two phase flow (VOF) MODEL 500 iteration 3 hour
any help me please
thanks

In general it is hard to say why there is such a big difference between both cases. We are talking about Fluent, right?

VOF models can be very complicated (with phase interaction solidification....)

Maybe you should proove you application, but a convenient act could be to discuss your final residuals and the evolution of them. If you have good residuals after 100 Iterations and the folowing 400 don't do a lot, you could stop your simulation at 100 iterations.

A big influence is also the setting of under relaxation factors in the solution controls.

P.S: I would write your next question in the CFX or Fluent sup-Forums.

thanks Jim87
yes i use fluent , i have two phase flow ( oil and water ) through in horizontal pipe ( d=0.508 m , l = 10 m ) stratified flow , i want compute pressure gradient , but i want applied pipe material (steel) effect on flow i select VOF .
MY PROBLEM
i don't no if my working is true or not
thanks