[Dabeet]

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

[ali_ebrahimi]

Originally Posted by Dabeet

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.

[GC94]

(${Time}< 0.005 ? 0.0002 : ((${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.