Hi Junting,
High memory footprint is not the only issue. Construction of the global
linear system for high-order polynomials is very expensive on modern
hardware (high memory requirements with low arithmetic intensity). Also
solving the linear system is challenging due to global communications.
You can read about implicit time-stepping on GPUs from
http://aero-comlab.stanford.edu/Papers/Dissertation_Jerry_Watkins-augmented.pdf
We are working on local implicit (pseudo) time stepping approaches, but
I'm afraid they won't be ready for the next release.
Regarding the dt/pseudo-dt ratio, I suggest keeping it in the range of
20-50. You can send me your case files if you want me to try it.
Thanks,
Niki
On 15/07/19 22:30, Junting Chen wrote:
Hello,
Any work ongoing to make the computation in pseudo time steps implicit?
As Niki mentioned, implicit pseudo time stepper caused storage issues
(in one of the posts). Any chance an implicit option can be offered in
the next release? Explicit forces pseudo dt being extremely small
therefore physical dt kind of small even though physical time stepper
is implicit. I am working on a bluff body problem. Aiming to reduce
the number of physical time steps within a vortex shedding cycle to be
around than 20, while now it has to be more than 300 to maintain
stability.
Thanks!
Junting Chen
--
You received this message because you are subscribed to the Google
Groups "PyFR Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to [email protected]
<mailto:[email protected]>.
To post to this group, send email to [email protected]
<mailto:[email protected]>.
Visit this group at https://groups.google.com/group/pyfrmailinglist.
To view this discussion on the web, visit
https://groups.google.com/d/msgid/pyfrmailinglist/a6ba9d83-aba8-4687-8864-ee2202574fbd%40googlegroups.com
<https://groups.google.com/d/msgid/pyfrmailinglist/a6ba9d83-aba8-4687-8864-ee2202574fbd%40googlegroups.com?utm_medium=email&utm_source=footer>.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "PyFR
Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send an email to [email protected].
Visit this group at https://groups.google.com/group/pyfrmailinglist.
To view this discussion on the web, visit
https://groups.google.com/d/msgid/pyfrmailinglist/52d52206-36e5-fd4c-5c34-40cc0c725467%40imperial.ac.uk.
For more options, visit https://groups.google.com/d/optout.
