The sliding mesh model allows you to set up a problem in which separate zones move relative to each other. The motion can be translational or rotational. The relative motion of stationary and moving components (for example, in a rotating machine) will give rise to transient interactions. Often, the transient solution that is sought in a sliding mesh simulation is time-periodic. That is, the transient solution repeats with a period related to the speeds of the moving domains.
The dynamic mesh model allows you to move the boundaries of a cell zone relative to other boundaries of the zone, and to adjust the mesh accordingly. The boundaries can move rigidly with respect to each other (that is, linear or rotational motion), and/or deform.
When deciding whether to use a sliding mesh versus a dynamic mesh, consider the following:
Many problems could be solved by either approach.
If the problem does not involve mesh deformation, the sliding mesh model is recommended, as it is simpler and more efficient.
The dynamic mesh method must be used if the mesh is deforming, or if the mesh motion is a function of the solution (for example, the six degrees of freedom solver).
Important: Sliding mesh and dynamic mesh are incompatible if they are combined within the same cell zone or adjacent cell zones. If you want to combine these two models within the same case file, they must be separated by a non-moving cell zone.
Note: By default, transient simulations that involve a rotating fluid zone utilize a better flow
field predictor that can speed up the calculation in some flow simulations. You can deactivate
the flow field predictor by using the command
solve/set/transient-controls/rotating-mesh-flow-predictor? and
answering no.
For examples of typical sliding mesh and dynamic mesh problems, see Introduction in the Theory Guide.