When you have specified the mesh update methods and their associated parameters, and you have defined the motion of dynamic zones, as described in Section 11.7.2, you can preview the motion of the mesh or the zone as it changes with time before you start your simulation. The same dynamic zone or mesh motion will be executed when you start your simulation.
Previewing Zone Motion
You can preview the motion of zones with rigid body motion using the Zone Motion panel (Figure 11.7.13) .
Display Zone Motion...
The zone motion preview only updates the graphical representation (in the graphics window) of the zones that you have selected using the Grid Display panel. The zone motion preview will only update those zones that have solid body motion specified. To use the Zone Motion preview:
You can also use the slider bar on the Zone Motion panel to fast-forward or rewind the motion of the selected zones. Previewing the zone motion can also be used as a postprocessor for 6DOF simulations (see Section 11.7.7).
Previewing Mesh Motion
The mesh motion preview is different from the zone motion described above in that the mesh connectivity is not changed.
To preview the dynamic mesh of a transient case, you can use the Mesh Motion panel (Figure 11.7.14) .
Solve Mesh Motion...
The procedure is as follows:
File Write Case...
| Note that the mesh motion will actually update the node locations as well as the connectivity of the mesh, so you must be sure to save your case file before doing the dynamic mesh motion. Once you have advanced the mesh by a certain number of time steps, you will not be able to recover the previous status of the mesh, other than by reloading the appropriate
FLUENT case file.
Note that if you turned on the in-cylinder model, the Time Step Size is automatically calculated from the Crank Angle Step Size and the Crank Shaft Speed that you have specified in the Dynamic Mesh Parameters panel.
See Section 4.3.4 for details about the use of this feature. This provides a convenient way for you to save results at successive time steps for later postprocessing.