****mesher
 ***mesh tube_3D.geof
  **open tube.geof
  **extension
   *elset R
   *distance 300.
   *num 10
 **bset_from_nset
  *nset_name inner_wall-ext
 **bset_from_nset
  *nset_name outer_wall-ext
 **bset_from_nset
  *nset_name bottom-ext
 **bset_from_nset
  *nset_name left-ext
 **bset z300
  *func z>299.999;
 **bset z0
  *func z<0.001;
****return