STAR-CCM+ allows cell sets to be created once you have a 3D volume mesh representation. The purpose of a cell set is to allow you to identify collections of cells that are useful for visualizing the model, such as during post processing or mesh checking. Any number of cell sets can be created for a given volume mesh, with each one containing anywhere from zero to the total number of cells in the model.
A cell set is similar to a derived part in many respects except that it is more versatile and can be derived from more than one condition. For example, you can create a cell set based on a combination of a threshold and a zone in order to obtain the cell grouping you want. For this reason it is a powerful tool for isolating and storing cell based parts for further use.
All operations relating to cell sets take place via the Cell Sets node, which appears under the Finite Volume Regions node in the Volume Mesh representation in the simulation tree:
A new cell set can be created based on a cell list, a scalar threshold or a zone. Once a cell set has been created, it can be modified if desired using a number of global options such as fill, clear, grow and shrink. Boolean operations are also possible to add to a set, take a subset of a set, remove from a set and replace a set altogether, using the same options as used to create the original set.
You should note that cell set operations only allow the groupings of cells that already exist in the model. No cells can be deleted or created by this process. The cell set operations described here are also currently only applicable to 3D meshes - if you have a 2D mesh then a cell set cannot be displayed.