Non repeatability issue

[Aldo Bonfiglioli]

Barry, Matt
I am back on the Non repeatability issue with answers
to your questions.

> 2) did you do the -ksp_rtol 1.e-12 at the same time as the -  
> vecscatter_reproduce? They
> must be done together. 

The enclosed plot (res_vs_step) shows the mass residual
history versus the Newton step counter.

For these same runs, the continuation parameter (CFL) shows similar jumps
being based upon the SER approach, see plot cfl_vs_its.pdf

> When you just fix the CFL and run Newton  runs to completion
> is it stable?

I have restarted the code from an almost fully converged solution
using infinite CFL and let it run for 30 Newton steps.
The behaviour is much more "reasonable" and the solution
remains within the steady state (see plot restarted....)

> Then if you ramp up the CFL much more slowly is it  stable and Newton
> convergence much smoother? 

I have not tried yet.
I know there exist smoother strategies
than SER to rump the continuation parameter
(I know this
http://www.cs.kuleuven.ac.be/publicaties/rapporten/tw/TW304.ps.gz
for instance)


Aldo

-- 
Dr. Aldo Bonfiglioli
Dip.to di Ingegneria e Fisica dell'Ambiente (DIFA)
Universita' della Basilicata
V.le dell'Ateneo lucano, 10 85100 Potenza ITALY
tel:+39.0971.205203 fax:+39.0971.205160


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