[Nek5000-users] Restarting with PNPN using PNPN-2 results
nek5000-users at lists.mcs.anl.gov
nek5000-users at lists.mcs.anl.gov
Wed Jun 15 03:44:04 CDT 2016
Hi,
I guess the question is whether there is a similar type of Uzawa
iteration also for Pnpn, this I don't know and I have not looked into
the theory. I can only say that for PnPn-2, with the nested iterations
you can get a perfect pressure (i.e. not proportional to Delta p) in one
time step. I guess one needs a PnPn user to answer that question.
Just as a side question; why do you want to go from PnPn-2 to PnPn? Out
of curiosity...
Best regards,
PHilipp
On 2016-06-15 00:44, nek5000-users at lists.mcs.anl.gov wrote:
> Philipp and Aleks,
>
> Thanks for the replies. The Uzawa method sounds exactly like what I am
> looking for. I would like to pay a penalty upfront to converge to a
> good pressure solution without taking too many (or really any) timesteps
> and then move forward with a resolved pressure solution. I am hoping
> there is a way to do this since a pressure projection method is being used.
>
> My solution is already well resolved temporally and I don't want to
> perturbe it with a long time series of unresolved pressure
> fields/slightly divergent velocity fields. Can anyone comment on the use
> of Uzawa with PNPN? Also, Philipp is there a specific routine you call
> to perform just one of these iterations? I haven't used this method before.
>
> Kind regards,
>
> Phil
>
> On Tue, Jun 14, 2016 at 11:00 AM,
> <nek5000-users-request at lists.mcs.anl.gov
> <mailto:nek5000-users-request at lists.mcs.anl.gov>> wrote:
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> 1. Restarting with PNPN using PNPN-2 results
> (nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>)
> 2. Re: Restarting with PNPN using PNPN-2 results
> (nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>)
> 3. Re: Restarting with PNPN using PNPN-2 results
> (nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>)
> 4. Re: lambda2 in turbChannel (nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>)
> 5. g2gi() no geometry found (nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>)
> 6. Re: g2gi() no geometry found (nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 13 Jun 2016 13:09:05 -0600
> From: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> To: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> Subject: [Nek5000-users] Restarting with PNPN using PNPN-2 results
> Message-ID:
>
> <mailman.23731.1465844987.24727.nek5000-users at lists.mcs.anl.gov
> <mailto:mailman.23731.1465844987.24727.nek5000-users at lists.mcs.anl.gov>>
> Content-Type: text/plain; charset="utf-8"
>
> Hello neks,
>
> I have a DNS simulation that I was running as PNPN-2 and I would like to
> run it as PNPN without starting back at the initial conditions.
> I am curious if anyone has experience running a PNPN case with initial
> conditions from a PNPN-2 simulation? I have tried this and the
> simulation
> runs okay, except the pressure term never seems to converge when running
> the PNPN simulation. This dramatically increases runtime and makes the
> results questionable. It seems to me that restarting with PNPN-2
> results
> should be doable, and that it should only take a few iterations for the
> pressure term to start converging. However, my simulation is still not
> converging after 100+ iterations, but it was converging fine when I was
> running PNPN-2.
>
> Any suggestions for things I should look for that might cause the
> problem,
> or potential fixes?
>
> Thanks
> --
> Phil Sakievich
>
> PhD Candidate - Mechanical Engineering
> Arizona State University - Ira A. Fulton School for Engineering of
> Matter
> Transport and Energy
> Tempe, Arizona
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>
> Message: 2
> Date: Mon, 13 Jun 2016 19:15:32 +0000
> From: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> To: "nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>"
> <nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>>
> Subject: Re: [Nek5000-users] Restarting with PNPN using PNPN-2 results
> Message-ID:
>
> <mailman.23735.1465845499.24727.nek5000-users at lists.mcs.anl.gov
> <mailto:mailman.23735.1465845499.24727.nek5000-users at lists.mcs.anl.gov>>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi Phil,
>
> The regularity of the pressure field is much larger for Pn-Pn as
> compared to Pn-Pn-2 so it should take some time to readjust to the
> larger resolution.
>
> Aleks
> ________________________________
> From: nek5000-users-bounces at lists.mcs.anl.gov
> <mailto:nek5000-users-bounces at lists.mcs.anl.gov>
> [nek5000-users-bounces at lists.mcs.anl.gov
> <mailto:nek5000-users-bounces at lists.mcs.anl.gov>] on behalf of
> nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> [nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>]
> Sent: Monday, June 13, 2016 2:09 PM
> To: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> Subject: [Nek5000-users] Restarting with PNPN using PNPN-2 results
>
> Hello neks,
>
> I have a DNS simulation that I was running as PNPN-2 and I would
> like to run it as PNPN without starting back at the initial conditions.
> I am curious if anyone has experience running a PNPN case with
> initial conditions from a PNPN-2 simulation? I have tried this and
> the simulation runs okay, except the pressure term never seems to
> converge when running the PNPN simulation. This dramatically
> increases runtime and makes the results questionable. It seems to
> me that restarting with PNPN-2 results should be doable, and that it
> should only take a few iterations for the pressure term to start
> converging. However, my simulation is still not converging after
> 100+ iterations, but it was converging fine when I was running PNPN-2.
>
> Any suggestions for things I should look for that might cause the
> problem, or potential fixes?
>
> Thanks
> --
> Phil Sakievich
>
> PhD Candidate - Mechanical Engineering
> Arizona State University - Ira A. Fulton School for Engineering of
> Matter Transport and Energy
> Tempe, Arizona
> -------------- next part --------------
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>
> ------------------------------
>
> Message: 3
> Date: Mon, 13 Jun 2016 21:31:08 +0200
> From: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> To: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> Subject: Re: [Nek5000-users] Restarting with PNPN using PNPN-2 results
> Message-ID:
>
> <mailman.23743.1465847039.24727.nek5000-users at lists.mcs.anl.gov
> <mailto:mailman.23743.1465847039.24727.nek5000-users at lists.mcs.anl.gov>>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> Hi,
>
> In principle, you can do a Navier-Stokes restart without pressure field.
> For PnPn-2 you can for instance do one step with Uzawa (nested
> iterations) to have a good pressure. So usually, when we do a restart of
> a solution wi
> thout pressure (e.g. when doing Arnoldi or Newton) then one Uzawa step
> fixes everything. I am not too familiar with PnPn, but I guess that
> there is a flavour that is not dependent on a previous pressure
> solution. Perhaps a PnPn-expert has some opinion on a Uzawa-like method?
>
> Best regards,
> Philipp
>
> On 2016-06-13 21:15, nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov> wrote:
> > Hi Phil,
> >
> > The regularity of the pressure field is much larger for Pn-Pn as
> > compared to Pn-Pn-2 so it should take some time to readjust to the
> > larger resolution.
> >
> > Aleks
> >
> ------------------------------------------------------------------------
> > *From:* nek5000-users-bounces at lists.mcs.anl.gov
> <mailto:nek5000-users-bounces at lists.mcs.anl.gov>
> > [nek5000-users-bounces at lists.mcs.anl.gov
> <mailto:nek5000-users-bounces at lists.mcs.anl.gov>] on behalf of
> > nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> [nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>]
> > *Sent:* Monday, June 13, 2016 2:09 PM
> > *To:* nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> > *Subject:* [Nek5000-users] Restarting with PNPN using PNPN-2 results
> >
> > Hello neks,
> >
> > I have a DNS simulation that I was running as PNPN-2 and I would
> like to
> > run it as PNPN without starting back at the initial conditions.
> > I am curious if anyone has experience running a PNPN case with initial
> > conditions from a PNPN-2 simulation? I have tried this and the
> > simulation runs okay, except the pressure term never seems to converge
> > when running the PNPN simulation. This dramatically increases runtime
> > and makes the results questionable. It seems to me that
> restarting with
> > PNPN-2 results should be doable, and that it should only take a few
> > iterations for the pressure term to start converging. However, my
> > simulation is still not converging after 100+ iterations, but it was
> > converging fine when I was running PNPN-2.
> >
> > Any suggestions for things I should look for that might cause the
> > problem, or potential fixes?
> >
> > Thanks
> > --
> > Phil Sakievich
> >
> > PhD Candidate - Mechanical Engineering
> > Arizona State University - Ira A. Fulton School for Engineering of
> > Matter Transport and Energy
> > Tempe, Arizona
> >
> >
> > _______________________________________________
> > Nek5000-users mailing list
> > Nek5000-users at lists.mcs.anl.gov
> <mailto:Nek5000-users at lists.mcs.anl.gov>
> > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >
>
>
> ------------------------------
>
> Message: 4
> Date: Mon, 13 Jun 2016 16:11:14 -0700
> From: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> To: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> Subject: Re: [Nek5000-users] lambda2 in turbChannel
> Message-ID:
>
> <mailman.23757.1465860244.24727.nek5000-users at lists.mcs.anl.gov
> <mailto:mailman.23757.1465860244.24727.nek5000-users at lists.mcs.anl.gov>>
> Content-Type: text/plain; charset="utf-8"
>
> Hi Wei,
>
> I do not think so. But you can definitely, modify the lambda2()
> routine to
> generate the Q criterion. It is quite straightforward.
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> ------------------------------
>
> Message: 5
> Date: Tue, 14 Jun 2016 11:21:16 +0200
> From: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> To: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> Subject: [Nek5000-users] g2gi() no geometry found
> Message-ID:
>
> <mailman.23773.1465903728.24727.nek5000-users at lists.mcs.anl.gov
> <mailto:mailman.23773.1465903728.24727.nek5000-users at lists.mcs.anl.gov>>
> Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
> format="flowed"
>
> Hello Neks,
>
> I am trying to use the g2gi subroutine, but keep getting the error
> massage ABORT: No geometry found in:
>
> call userchk
> grid-to-grid interpolation
> 140 8 8 8 2.0010000E+03 4002 U P 4
> NELT,NX,N ?a?@
>
> NONSTD HDR, parse_hdr, abort.
> ABORT: No geometry found in newgeom.fld
>
> call exitt: dying ...
>
> Anybody familiar with this error? Do I give him the wrong files? I
> assumed Nek wants a .fld. Any help or working case as an example would
> be highly appreciated.
>
> Br
> Michael
> e1429308 at student.tuwien.ac.at <mailto:e1429308 at student.tuwien.ac.at>
>
>
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Tue, 14 Jun 2016 11:40:05 +0000
> From: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> To: "nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>"
> <nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>>
> Subject: Re: [Nek5000-users] g2gi() no geometry found
> Message-ID:
>
> <mailman.23774.1465904407.24727.nek5000-users at lists.mcs.anl.gov
> <mailto:mailman.23774.1465904407.24727.nek5000-users at lists.mcs.anl.gov>>
> Content-Type: text/plain; charset="us-ascii"
>
>
> Hi Michael,
>
> You need to compile with the ifmpiio flag set in makenek:
>
>
> # (set PPLIST=? to get a list of available symbols)
> PPLIST="MPIIO"
>
> All files should be .f00000 files, which is the current default.
> (Make certain that your
> current .usr file does not reset param(66) to 4.) [ You can
> convert a .fld file to a .f0000
> file by running a 0 step, 0 FINTIME job and setting p66=6, p67=4 in
> the .usr file, say, in
> subroutine usrdat(). ]
>
> When running g2gi, make certain that the new file has the geometry
> in it. The old file does not need the
> geometry, only the data to be interpolated.
>
> hth
>
> Paul
>
>
> ________________________________________
> From: nek5000-users-bounces at lists.mcs.anl.gov
> <mailto:nek5000-users-bounces at lists.mcs.anl.gov>
> [nek5000-users-bounces at lists.mcs.anl.gov
> <mailto:nek5000-users-bounces at lists.mcs.anl.gov>] on behalf of
> nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> [nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>]
> Sent: Tuesday, June 14, 2016 4:21 AM
> To: nek5000-users at lists.mcs.anl.gov
> <mailto:nek5000-users at lists.mcs.anl.gov>
> Subject: [Nek5000-users] g2gi() no geometry found
>
> Hello Neks,
>
> I am trying to use the g2gi subroutine, but keep getting the error
> massage ABORT: No geometry found in:
>
> call userchk
> grid-to-grid interpolation
> 140 8 8 8 2.0010000E+03 4002 U P 4
> NELT,NX,N ?a?@
>
> NONSTD HDR, parse_hdr, abort.
> ABORT: No geometry found in newgeom.fld
>
> call exitt: dying ...
>
> Anybody familiar with this error? Do I give him the wrong files? I
> assumed Nek wants a .fld. Any help or working case as an example would
> be highly appreciated.
>
> Br
> Michael
> e1429308 at student.tuwien.ac.at <mailto:e1429308 at student.tuwien.ac.at>
>
>
>
>
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov <mailto:Nek5000-users at lists.mcs.anl.gov>
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
>
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>
> _______________________________________________
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> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
>
> End of Nek5000-users Digest, Vol 88, Issue 13
> *********************************************
>
>
>
>
> --
> Phil Sakievich
>
> PhD Candidate - Mechanical Engineering
> Arizona State University - Ira A. Fulton School for Engineering of
> Matter Transport and Energy
> Tempe, Arizona
>
>
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
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