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Old   December 3, 2011, 01:02
Default iteration problem
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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.
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Old   December 3, 2011, 04:14
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just try to use a much higher order schemes like quick and coupled and use much less time step.

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Old   December 3, 2011, 07:07
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Use smaller mesh.Maybe it works.
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Old   December 3, 2011, 08:04
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Quote:
Originally Posted by mashinsazi View Post
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)
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Old   December 3, 2011, 13:54
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use higher order schemes it will work in ur pv
there is no problem in using higher order schemes in it

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