Cubit 16.04 User Documentation
To partition a volume by giving a center and radius:
Partition Create Volume <id> Center [Location] {options} Radius <val>
This command splits the existing volume into two volumes. All volume elements that lie within the specified radius of the specified center location are identified, and the exterior faces of these elements are used to create a surface and partition the volume. The center can be specified with any of the location options.
Figure 1 shows an example of a partitioned volume. A cube that has been map meshed is partitioned using a center at one of its vertices. The result is two distinct volumes with a surface separating the two. The interface surface is composed of the faces of the interior hex elements.
This command may be useful for separating small regions of a meshed volume so that remeshing or mesh improvement may be performed locally.