Ansys Fluent Tutorial | Overset Mesh

Source: Ansys

Whereas non-conformal interfaces connect cell zones along matching face zones, overset interfaces connect cell zones by interpolating cell data in the overlapping regions. For overset meshing to be successful, the cell zones must overlap sufficiently. An advantage of overset meshing is that the individual parts of an overset mesh can be generated independently and with fewer constraints than if the parts had to fit together conformally or along non-conformal interfaces. This can make it easier to replace parts of a mesh without having to remesh large parts or even the complete mesh.

Figure 6.49: Overset Component and Background Mesh shows a simplified mesh for a simulation of flow over a cylinder in a duct. The mesh consists of two parts—a background mesh representing the duct and a separate component mesh around the cylinder. The case is set up in Fluent as an overset case by specifying the outer boundary of the cylinder mesh as overset (boundary type), and by creating an overset interface containing the two cell zones. With these two steps complete, Fluent automatically establishes the necessary connectivity between the meshes when the flow is initialized. In this process, cells that fall outside the computational domain are classified as dead cells. The cells where the flow equations are solved are referred to as solve cells. Receptor cells receive data interpolated from another mesh. The donor cells—the cells where the receptors get their data—are a subset of the solve cells. For the above case, Figure 6.50: Solve Cells After Initialization shows the solve cells of the mesh after the flow is initialized. Note that in parallel, you can print partition statistics to get information about some of the cell classifications, as described in Interpreting Partition Statistics.

In this tutorial you will learn how to create geometry and its meshing using several tools in DesignModeler and Ansys Meshing, then you will learn how to simulate the model using Ansys Fluent.