[Nek5000-users] Setting up a case from scratch

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

Try running 'mbsize' on the gmsh file, and check the number of vertices to make sure it's getting all of them.  Or, run 
mbsize -ll, piping the output to a file, and check one of the hexes to make sure it's 27-noded.  If that's the case, 
we're all set (modulo how to handle the BC's).

- tim

On 11/28/2012 09:12 AM, nek5000-users at lists.mcs.anl.gov wrote:
> Thanks Tim. Gmsh+moab was my next question and you answered it.
>
> I will try to see if it works. I made a mesh in gmsh with quadratic elements and mbconvert was able to convert it,
> atleast I get no error. Does this mean that nek will be able to use the curved element information contained in the mesh
> ? I see that gmsh can generate upto 5'th order elements (degree 5).
>
> In gmsh I can group boundary faces into sets which are identified by an integer tag, which should help in specifying
> boundary condition.
>
> praveen
>
> On Wed, Nov 28, 2012 at 8:17 PM, <nek5000-users at lists.mcs.anl.gov <mailto:nek5000-users at lists.mcs.anl.gov>> wrote:
>
>     Note that this should be relatively trivial to do with the MOAB-based version of Nek (MOAB can read gmsh meshes
>     already).  I'm not sure whether you can specify higher-order hexes in gmsh, but if you can, start by generating
>     those (27-node hex).  Building and running Nek on MOAB is described in the Nek user's guide and on the nek wiki.
>       The examples/moab problem is a MOAB-based one, showing how to do this for a fluid-only problem; moab_conjht
>     demonstrates it for a fluid/solid problem.  Note that the user documentation on text input is a bit out of date, so
>     refer to the moab example rather than the user's guide for that (will take this as an indication I need to update
>     the user's guide and wiki).
>
>     As for boundary conditions, I'm not sure how this is represented in the gmsh files (whether groups of nodes/faces
>     are indicated in the file, or whether a field on nodes/faces/sides is used to indicate this).  If the former, these
>     should read into MOAB sets marked with NEUMANN_SET or DIRICHLET_SET tags; if the latter, you'll have to interpret
>     this data in the .usr file to set the boundary conditions.
>
>     MOAB's gmsh reader is not parallelized, so if you want to run this problem in parallel, you'll need to translate
>     into MOAB's .h5m file format, then partition, as described in the wiki instructions.  Building MOAB builds also
>     'mbconvert', which converts between any file formats read/written by MOAB (for that matter, partitioning with MOAB's
>     tool would allow you to read the gmsh file directly and output the partitioning info with the mesh to .h5m).
>
>     - tim
>
>
>
>
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"You will keep in perfect peace him whose mind is
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              Tim Tautges            Argonne National Laboratory
          (tautges at mcs.anl.gov)      (telecommuting from UW-Madison)
  phone (gvoice): (608) 354-1459      1500 Engineering Dr.
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