The .ngeom file type was originally for use with the COMET solver but is now being superseded by the CCM format. The .ngeom format is exported by pro-STAR using the NGEOM command and can only contain mesh data.
If the appropriate scale factor was applied during the export process then the vertices contained in the file conform to SI and no further action is required on importing the file into STAR-CCM+. The scale factor used is also saved to the file but is not used. Boundary types are inferred from boundary names, and if no inference can be made, then a boundary is assigned the type wall.
Each collection of cells with the same properties (material label, material index, porosity index, spin index and group index) in pro-STAR is considered to be one region. Cell types do not affect the region definition unless one of the above properties differs.
The STAR-Design solid-modeling software by CD-adapco can also export meshes using the NGEOM file format. Please see the appropriate user guide for this package for more information on how to do this.