For the past 30 years, the ability to perform Computational Fluid Dynamics simulations of rotating objects has been severely curtailed by the need to generate an interconnected mesh between the objects (for example between a rotating impeller and mixer geometry). Not only did this requirement make the creation of "moving mesh" simulations an intensive manual process, it also often rendered it impossible in the case of objects with very close interaction.
Advanced meshing in STAR-CCM+ provides two easy-to-use motion options for time-accurate simulations of rotating components:
Rigid body motion (sliding mesh)
Allows parts of the domain to rotate and/or translate and with respect to each other and uses a sliding interface at the boundaries, yielding time accurate flow data that includes the effects of transient interactions between components.
Overset (Chimera) meshing allows bodies to move and rotate freely throughout the computational domain without being artificially constrained by the mesh, allowing the simulations of very close moving bodies. Separate overlapping meshes are used, a background mesh, and a body fitted mesh around the moving geometry of interest. The body and fitted mesh are then able to move freely without the need to re-mesh, and data is interpolated between the two meshes. This is a game-changing feature for the simulation of multiple moving objects.
Both the Rigid Motion and Overset Mesh capability are fully compatible with the full range of unstructured meshing options in STAR-CCM+. With no need to worry about interconnecting meshes or cell distortion, this capability brings genuine moving object simulation within the grasp of all engineers.