Set up the Simulation

3D Simulation

Perform the simulation on the entire solution domain. 3D Simulation is a more rigorous way to simulate flow aerodynamics, and is useful for visualizing the interactive nature of the flow around the object. Results computed in 3D are more complete than in 2D because they encompass the entire object and the air throughout the wind tunnel. Use 3D to see where the flow is smooth and where it changes direction. Look for regions that show flow separation, recirculation, and abrupt direction changes.

2D Simulation

Perform the simulation on a single slice through the solution domain. This mode is the fastest, and produces results on a two-dimensional slice through the model. Use it to quickly understand the aerodynamic behavior through a specific cross-section. Note that while results produced in 2D mode are conceptual, they provide a quick and valuable view of how the air moves past the design. The displayed results update as you change the wind speed and direction.

Resolution

Increase or decrease the voxel element size. A larger element size typically runs faster, but is less accurate than a smaller voxel element size. In the following example, the mesh size is much too coarse:

When the mesh resolution is increased, the results look much better:

Domain Size

To change the size and position of the air volume around the object, select the direction and use the up and down arrows to grow or shrink the domain:

It is important to select an appropriate size for the flow domain to ensure that bounds to not artificially influence the flow. Click here for more about sizing the domain correctly.

Compass

With the compass, you can interactively control the wind direction and speed. This direct interaction is convenient for varying simulation parameters quickly and easily.

To set the wind velocity, drag the slider ball at the compass tail:

To set the wind direction, drag the slider ball around the direction arc:

To disable the display of the compass, click Compass to toggle its display.