If there are multiple mesh assemblies that have matched meshes,
you can try to glue these together by selecting the assemblies in
the tree view (using the Ctrl key), right-clicking,
and selecting Glue Regions from the shortcut
menu. If the meshes match exactly, a 1:1 connection is made; otherwise
a GGI connection is used. In either case, the connection appears as
a mapping of two regions under Connectivity in
the tree view (for example, F3.B1.P3<->F3.B2.P4). Note that you can select Connectivity > Hide 1:1 Connections so that the list of GGI connections
is easier to work with.
Important: Merging/connecting meshes in CFX-Pre is not supported when those meshes are provided by Ansys Workbench during a Workbench session. Doing so may result in extra copies of these meshes appearing when refreshing meshes.
Tip: Another way to glue two meshes together is to right-click
Connectivity from
the tree view and select Define Connection.
In the Mesh Connections Editor that appears,
click Select from extended list 
to browse the Selection
Dialog for the regions to choose for Side One
and Side Two. If Highlighting 
is selected, the regions are highlighted in the
viewer as you highlight regions in the Selection Dialog.
If a pair of meshes cannot be glued together, you can use a domain interface instead. For details, see Domain Interfaces.
Note:
There is limited checking of the validity of GGI connections created by gluing meshes together.
When you transform or copy multiple assemblies, it is possible to have each copy glued to its original assembly or to other copies made. For details, see Advanced Options in the Transform Mesh Command section.
For more information on mesh connection types, see Mesh Connection Options in the CFX-Solver Modeling Guide.