iteration problem
 

i have this kind of problem, in all case if i set the solution method to 1st order, the iterations would be converged for the first few time steps, after that, the iterations can't come to converge point. but if i set to 2nd order, then all the iterations can't go to converge point.

i have tried time step from 0.001, 0.005, 0.01, 0.02, 0.05s, all react the same.

my case is a fan blowing 1.48m/s hot air to dry a piece of cotton fiber which is 0.15m away.
is the time step still too large for it? or i have done something wrong?

below is how the iterations look like when i use 1st order.

Hi
 

just try to use a much higher order schemes like quick and coupled and use much less time step.

SHK

Use smaller mesh.Maybe it works.

is there any alt. method?
i am a student and my pc has only 8GB of ram, cannot afford to have a powerful computer to run it. (what i mean running slowly is the most worst case for me)

hi
 

use higher order schemes it will work in ur pv
there is no problem in using higher order schemes in it

SHK