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Confuse on initial condition and velocity profile v(0)=0

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Old   September 17, 2015, 08:38
Smile Confuse on initial condition and velocity profile v(0)=0
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Dear all,

I am confused on the role of initial condition in the transient laminar flow practice and hope someone can explain to me.

e.g. if I have definite my initial velocity as the maximum flow rate of my entire velocity profile, such as v= 0.5m/s which I have the respective pressure magnitude which I achieved through the steady solution. when I input my velocity profile as inlet profile of a tube, I start with v(0)=0, may I know which one fluent solver will use as its starting point for the iterations for better convergence?

I am quite worried about initial condition. as it looks to me that if it start with v(0)=0.5m/s, then what if my v(0.01)=0.1m/s, shouldn't it a big problem for solver to converge from 0.5 to 0.1m/s?

hope someone can explain it to me.
thank you.
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Old   September 18, 2015, 11:21
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The initial conditions apply only to the interior cells. The boundary conditions are also imposed on the boundaries. So for interior cells the initial velocities would be the initial conditions. For boundary faces, the initial velocities would be taken from your boundary conditions.
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Old   September 19, 2015, 00:26
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Quote:
Originally Posted by LuckyTran View Post
The initial conditions apply only to the interior cells. The boundary conditions are also imposed on the boundaries. So for interior cells the initial velocities would be the initial conditions. For boundary faces, the initial velocities would be taken from your boundary conditions.
Thanks for your help. it make things clear for me.
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