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Divergence when TI of inlet is low

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Old   April 27, 2015, 18:33
Default Divergence when TI of inlet is low
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buidu
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Dear all,

I am running a simulation to study convective heat loss from cylinder. When I set the the boundry of inlet with a turbulent intensity(TI) of 5%, it can converge very well. However, when I set the Ti as 0.1%, the calculation divergeced at around 50 steps. If I want to run a simulation with low TI, e.g. 0.1%, does anyone know how should I set the boundry condition? The calculation domain is in the attachment.

Thank you very much.

Regards,
Hao
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Old   April 27, 2015, 22:03
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Are you changing only the TI at the inlet? What about the initialization? The initialization is very important. You need to adjust the value of k, epsilon/omega to better guesses.
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Old   April 28, 2015, 04:02
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Quote:
Originally Posted by LuckyTran View Post
Are you changing only the TI at the inlet? What about the initialization? The initialization is very important. You need to adjust the value of k, epsilon/omega to better guesses.
I just changed the TI. I tried to change other parameters, but I cannot find any reference on how to calculate them. The tutorial that Ansys provides only gives the assumption when the flow is fully developed. Could you give my some hints on it? How should I calculate the parameters? Thank you very much.

Hao
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