Wind Tunnel
You can modify the dimensions of the wind tunnel in a dialog box or graphically. To open the dialog box, double-click the Wind Tunnel item in the Data navigator or open the Edit menu, point to Wind Tunnel and select Edit Wind Tunnel.
The size of the wind tunnel is defined by means of six parameters; the dimensions in X, Y and Z refer to the origin. The [Adjust to Model Standing on the Ground] button enables you to reset the size to the default dimensions for any model located on the terrain. [Adjust to Model Flying in the Air], however, creates a wind tunnel for a model whose bottom surface is at a considerable distance from the terrain. [Adjust Graphically] closes the dialog box and opens the feature described below.
It is recommended to adjust the work plane grid to the size of the wind tunnel. The "Slip" boundary condition for the bottom boundary of the wind tunnel deactivates the influence of the horizontal plane at its bottom surface, i.e. as if the object was far off the ground. This option enables you to analyse parts of the model, for example the top of a tower, without defining the entire building.
To modify the wind tunnel graphically, click the Resize Wind Tunnel item in the panel. Make sure that the Model tab of the work window is set.
In the same way as described above, it is possible to enter the dimensions of the wind tunnel in the Edit Bar panel. Additionally, you can modify its size in the work window by selecting one of the arrows and moving it. The corresponding parameters are updated in the panel.
When you hold the [Shift] key while moving an arrow, the wind tunnel is modified symmetrically in the respective direction. By holding the [Ctrl] key, you can scale the wind tunnel up or down uniformly in all three directions.
Note
The default dimensions of the wind tunnel are set as small as possible to obtain short calculation times. If the simulation is divergent, one of the reasons may be that the length of the wind tunnel in X-direction is too short, especially the area behind the object. You should then extend the wind tunnel accordingly.