[FLASH-USERS] parameters changes allowed on restart?

[Andrew Szymkowiak]

dongwook at flash.uchicago.edu wrote:
> Dear Andrew,
>
> The original implementation works correctly for a normal situation
> in which dr_dt is also a value that is being read from a checkpoint
> file for a restart.
>
> Therefore, it is an expected behavior that you saw your run got restarted
> with the old small timesteps, because that was the value you used
> in your previous run, and got checkpointed.
>
> Note that dtmax is a ceiling value (upper limit) that keeps your dr_dt
> from growing more than what you expect, and I don't think this is
> not what you wanted: I think what you want to have is "dtmin"
> (a floor value) in order to restart with a larger dt than dr_dt.
>
>   
Thanks Dongwook.  I did try a restart where I set dtmin to a larger 
value, but the simulation continued advancing at only that value, and
never started increasing the timestep size towards the dtmax value as 
the hydro conditions permit.  I probably should not just put in the
large value that it will rise to at the end of the simulation for the 
dtmin value, because early in the restart, the temps are too high (or the
density contrasts too large, etc) and it needs to start off with smaller 
steps.  I might mention that this situation probably means that a
long run, broken  in half, won't get to the same point after a restart, 
as the timesteps no longer will increase.

Best,  Andy