# Field function for variable time step

 Register Blogs Members List Search Today's Posts Mark Forums Read

 February 26, 2021, 10:41 Field function for variable time step #1 New Member   Dabeet Sathyanarayan Join Date: Feb 2021 Posts: 1 Rep Power: 0 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

February 27, 2021, 08:05
#2
New Member

ali_Ebrahimi
Join Date: Jan 2021
Posts: 9
Rep Power: 5
Quote:
 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.
Attached Images
 2021-02-27_4-58-33.png (79.2 KB, 45 views)

 March 26, 2021, 15:55 #3 New Member   Gokhan Join Date: Dec 2020 Location: Stockholm Posts: 5 Rep Power: 5 (\${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.

 Tags field function, iterations per time step, time step