By default, Ansys Polyflow will optimize and (if necessary) decompose the mesh before it begins the calculation. If you want Ansys Polyflow to use a mesh that you have already optimized and/or decomposed (using either your mesh generator or Ansys Polydata), you will need to make sure that you have selected the classic direct solver (see Selecting the Solver) and then start Ansys Polyflow with the -opt msh command line option:

 polyflow -opt msh < my.dat 

or

 polyflow -opt msh < my.dat > my.lst 

When Ansys Polyflow is started with this option, it will not perform any optimization or decomposition of the mesh. Instead, it will use the mesh file identified in the data file without making any changes to it.