You can use PreBFC to create two different types of grids for FLUENT, structured quadrilateral/hexahedral and unstructured triangular/tetrahedral.
Structured Grid Files
To generate a structured 2D or 3D grid, follow the procedure described in the PreBFC User's Guide (Chapters 6 and 7). The resulting grid will contain quadrilateral (2D) or hexahedral (3D) elements. Do not specify more than 70 wall zones and 35 inlet zones.
To import the grid, use the File/Import/PreBFC File... menu item, as described in Section 4.11.17.
To manually convert a file in PreBFC format to a mesh file suitable for FLUENT, enter the following command:
The output file produced can be read into FLUENT using the File/Read/Case... menu item, as described in Section 4.2.
Unstructured Triangular and Tetrahedral Grid Files
To generate an unstructured 2D grid, follow the procedure described in the PreBFC User's Guide. Save the mesh file in the RAMPANT format using the MESH-RAMPANT/TGRID command. The current FLUENT format is the same as the RAMPANT format. The resulting grid will contain triangular elements. To import the grid, use the File/Read/Case... menu item, as described in Section 4.2.
To generate a 3D unstructured tetrahedral grid, follow the procedure described in Chapter 8 of the PreBFC User's Guide for generating a surface mesh. Then read the surface mesh into TGrid, and complete the grid generation there. See Section 6.3.3 for information about TGrid grid files.