Regions are assigned types that models within their associated continuum use to determine what specific conditions and values are required.
STAR-CCM+ recognizes three different region types: fluid, porous and solid. The availability of each type depends on the continuum associated with the region. Fluid and porous regions are available only if the continuum is a gas or liquid. Solid regions are available only if the continuum is a solid.
Region types are initially assigned by STAR-CCM+ upon mesh import (based on information contained in the mesh being imported), but may be reassigned within STAR-CCM+.