[Nek5000-users] Increase DT in Usrchk based on CFL

[nek5000-users at lists.mcs.anl.gov]

Hi, 



I would like to increase my DT dynamically by checking the current CFL at each step.  For example: 



if C < 0.15 then  param(12) = param(12) + 1E-05  



I know I can adjust the time step in usrchk by setting param(12), but can I access C in the same manner by param(26)? Or is this only the parameter I set in the rea, and it is accessed by another variable? 



This issue occurs after a few 100 steps where my C drops and starts to settle around 0.1-0.15.  The problem is I'm not sure that it always occurs around the same time steps, and there for would like to adjust it based on the actual value. I know nek will adjust DT if my C becomes too large, but when C becomes too small is the issue DT is not adjusted so long as it meets what I set in the rea . 



Thanks for any insight! 



-Michael 
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