When creating a sliding mesh simulation, mesh each part separately, and ensure that none of the meshes connect. In the valid configuration described previously, the following three mesh regions were required:

Note that edge bs5 is separate and coincident to bs2. During the simulation, as nodes on edges bs5 and bs2 slide past each other, the solver will interpolate flow variables across the disconnected mesh. Specific interface boundary conditions are required to couple sliding meshes together. Figure 23.3: The Mesh of the Surrounding Domain SD1 shows the mesh of the surrounding domain (SD1).

Figure 23.3: The Mesh of the Surrounding Domain SD1

Figure 23.4: The Sliding Meshes shows the mesh of the domains (SD2 and SD3) attached to each moving part. It contains two internal boundaries, bs4 and bs6, and two external boundaries, bs5 and bs7. The internal boundary bs2 of SD1 must be tangential to the external boundary bs5 of SD2.

Figure 23.4: The Sliding Meshes

Similarly, bs3 of SD1 must be tangential to bs7 of SD3. The element size on both boundaries should be same for more accuracy.

In the transient simulation, rotate the mesh SD2 (or SD3) at the same angular velocity prescribed along its internal boundary bs4 (or bs6). Use the non-conformal method to connect the velocity nodes of bs2 (or bs3) to the corresponding nodes of bs5 (or bs7). For additional information on the non-conformal method, see Non-Conformal Boundaries.