[Nek5000-users] par file and moving mesh

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

Marco,

please note that the .par file is still experimental and not as robust as the good old .rea.
It looks like I forgot to support the viscosity and tolerance for the mesh elasticity solver - so the default values 0.4 and 0.02 will be used. Anyway, your mesh should be moving unless there is something wrong with the BC in the exo case.

Cheers,
Stefan

-----Original message-----
> From:nek5000-users at lists.mcs.anl.gov <nek5000-users at lists.mcs.anl.gov>
> Sent: Monday 23rd October 2017 22:15
> To: nek5000-users at lists.mcs.anl.gov
> Subject: Re: [Nek5000-users] par file and moving mesh
> 
> Hi all,
> 
> I have an update on this issue.
> 
> The mesh I am using was generated in Cubit and then converted to the Nek5000 re2 format using the exo2nek script. I call the function ‘gen_rea’ to make Nek5000 write the mesh in a rea file. My mesh has a moving boundary condition, and the mesh motion is computed by the ALE solver. I then do the following:
> 	1) I run my session using the mesh read from the re2 file that comes from the exo2nek script.
> 	2) I run my session using the rea file that was generated by the function call ‘gen_rea'.
> 
> In the first case, the output file does not show the mesh motion even though the velocity profile seems correct. In the second case, the mesh motion shows in the output file when I visualize the solution with Visit.
> 
> Is this a bug, or simply a misuse of the exo2nek script?
> 
> Marco
> 
> > On Oct 19, 2017, at 8:51 AM, nek5000-users at lists.mcs.anl.gov <Nek5000-users at lists.mcs.anl.gov> wrote:
> > 
> > Hi all,
> > 
> > I am trying to switch from a rea file to a par file and I am having difficulties with the moving mesh capabilities. When visualizing the numerical solution, the mesh is not moving, whereas it was moving with a previous version of Nek5000.
> > 
> > I copied the par file from the my_cyl examples as a start point. The main different between my session and the mv_cyl session is the way the mesh motion is handled. I believe the mesh velocity is provided by the user through a function, whereas in my session the mesh velocity is solved for.
> > 
> > Below is the par file I am currently using:
> > 
> > #
> > # nek parameter file
> > #
> > [GENERAL]
> > #startFrom = restart.fld
> > stopAt = numSteps
> > endTime = 0
> > numSteps = 1000
> > 
> > dt = 1e-03
> > timeStepper = bdf #bdf #char #steady
> > tOrder = 3
> > variableDt = no
> > maxCFL = 2.0
> > 
> > writeControl = timeStep #runTime
> > writeInterval = 50
> > 
> > dealiasing = yes
> > userParam01 = 1.16
> > userParam02 = 1.8550800E-05
> > 
> > [PROBLEMTYPE]
> > lowMachNumber = no
> > variableProperties = yes
> > dp0dt = no
> > 
> > [MESH]
> > motion = yes
> > meshVelocity = no
> > 
> > [PRESSURE]
> > residualTol = 1e-10
> > residualProj = no
> > #preconditioner = amg
> > 
> > [VELOCITY]
> > residualTol = 1e-12
> > residualProj = no
> > 
> > 
> > Any help will be appreciated.
> > 
> > Thanks,
> > 
> > Marco
> > 
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> > 
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