How can I set relative North?
Ventus supports Wind direction adjustments differently than ContamW; remember, in Ventus the user models actual geometry. From the relevant section of the Ventus User Manual:
The Ventus global coordinate system has x-y-z axes in the lower left corner of the 2D/3D Workspace. Wind directions are defined relative to the global coordinate system. North is aligned with the positive y-axis; East is aligned with the positive x-axis.
In keeping with this approach, rotate the model geometry to match its intended build orientation (let relative North remain 0.0°).
Use the Rotate Tool:
- You should be in 3D Mode or 2D Top View so that the model defaults to rotation about the z-axis.
- Select the entire model, including zones, flow paths, AHS points, and source/sink objects.
- Select the Rotate Tool.
- Single-click to specify the rotation center.
- Single-click another point to define a reference vector from the first point to the second point. This reference vector is what the angle is based from.
- Single-click a third point to define the angle vector from the first point to the third point.
Alternatively, you can manually enter a rotation Angle value in the Properties panel. The rotation center values (current selection center) populate the properties Rotate Base X and Rotate Base Y by default when the Rotate Tool is selected.
The orientation of the model relative to the Ventus global coordinate system is input to ContamX when modeling wind.
In the Weather and Wind dialogue, the Relative North wind modifier is not used in calculations. Future versions of Ventus will remove this entry box to avoid confusion.
We hope that this system meets your needs, and we remain open to feedback. For more information, please contact Thunderhead Engineering for support: support@thunderheadeng.com.