ValueError: Unpaired faces in mesh

[Ezhilmathi Krishnasamy]

Hi, 

I am getting an error for the mesh conversion of simple 3D model (sphere in the fluid domain)

(root) tegner-login-1$ pyfr import -t gmsh sphere1.msh sphere.pyfrm
Traceback (most recent call last):
  File "/cfs/klemming/nobackup/k/kriezh/ANACONDA_TEGNER/bin/pyfr", line 11, in <module>
    load_entry_point('pyfr==1.7.0', 'console_scripts', 'pyfr')()
  File "/afs/pdc.kth.se/roots/srv/tegner/v1.8/cfs/klemming/nobackup/k/kriezh/ANACONDA_TEGNER/lib/python3.6/site-packages/pyfr-1.7.0-py3.6.egg/pyfr/__main__.py", line 110, in main
  File "/afs/pdc.kth.se/roots/srv/tegner/v1.8/cfs/klemming/nobackup/k/kriezh/ANACONDA_TEGNER/lib/python3.6/site-packages/pyfr-1.7.0-py3.6.egg/pyfr/__main__.py", line 124, in process_import
  File "/afs/pdc.kth.se/roots/srv/tegner/v1.8/cfs/klemming/nobackup/k/kriezh/ANACONDA_TEGNER/lib/python3.6/site-packages/pyfr-1.7.0-py3.6.egg/pyfr/readers/base.py", line 23, in to_pyfrm
  File "/afs/pdc.kth.se/roots/srv/tegner/v1.8/cfs/klemming/nobackup/k/kriezh/ANACONDA_TEGNER/lib/python3.6/site-packages/pyfr-1.7.0-py3.6.egg/pyfr/readers/gmsh.py", line 200, in _to_raw_pyfrm
  File "/afs/pdc.kth.se/roots/srv/tegner/v1.8/cfs/klemming/nobackup/k/kriezh/ANACONDA_TEGNER/lib/python3.6/site-packages/pyfr-1.7.0-py3.6.egg/pyfr/readers/base.py", line 194, in get_connectivity
ValueError: Unpaired faces in mesh


I guess, am making some mistake in gmsh, but it looks OK to me, could some one take a
quick look and let me know where I am making mistake.

Kind regards,
Mathi

[nnunn]

Hi Ezhilmathi,

The mesh is not getting the sphere boundary faces defined as a "physical" surface.

But it seems to work if you change your line for Physical Surface("sphere") = ...

// Surface loop for volume definition

Surface Loop(29) = {14, 16, 18, 20, 22, 24, 26, 28};

// Physical Surface("sphere") = {29};    // old version

Physical Surface("sphere") = {14, 16, 18, 20, 22, 24, 26, 28};  //  <= try this

Nigel