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Field function for variable time step

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Old   February 26, 2021, 10:41
Default Field function for variable time step
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Dabeet Sathyanarayan
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I want to create a field function for variable time step duration,
i.e, if time is less than 1 min, time step size is 10 secs, after thatc, time step size is 1min for next 10 mins.

or, alternatively, for the first time step, i want 5000 iterations, after that i need 1000 iterations per time step.

How to i do this, Any help appreciated, thanks
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Old   February 27, 2021, 08:05
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ali_Ebrahimi
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Quote:
Originally Posted by Dabeet View Post
I want to create a field function for variable time step duration,
i.e, if time is less than 1 min, time step size is 10 secs, after thatc, time step size is 1min for next 10 mins.

or, alternatively, for the first time step, i want 5000 iterations, after that i need 1000 iterations per time step.

How to i do this, Any help appreciated, thanks
You can use the "Adaptive time step" option available in the Physics section of the problem.
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Old   March 26, 2021, 15:55
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Gokhan
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(${Time}< 0.005 ? 0.0002 : ((${Time} < 0.04 ? 0.00164 : ${Time} < 4.2 ? 0.0012 : ((${Time} < 4.6 ? 0.0002 : 0.0001 )))))

Maybe something like that can work for you. It means when the physical time is less than 0.005-timestep is 0.0002. If the physical time is bigger than 0.005 then the timestep is 0.00164. You can just copy and paste it to timestep part and alter the boundaries according to your simulation.
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