Model Dimensions

The ultraFluidX 2023.0 Setup guidelines for vehicle aerodynamics, provides various setup recommendations which rely on the model dimensions and position. HMCFD’s Case Setup environment allows you to gather this information through the GUI and the Python Window.

Python Window

  1. Open the Python Window by going to View > Python Window or pressing F4 on your keyboard.
  2. Execute the following:
    • from hwx import inspire
    • model = inspire.getActiveModel()

    • model.axisAlignedBoundingBox

      Output: Box(x=4.96514, y=2.1354, z=1.42625)

    • model.axisAlignedBoundingBox.minMax

      Output: (Point (-0.9074339866638184, -1.0676989555358887, -0.010730000212788582),

      Point (4.057706832885742, 1.0676989555358887, 1.415518045425415))

GUI

  1. Select all parts in the viewer.
  2. Click on the Measure tool.
    Figure 1.
    A bounding box fitted to the selected parts will show along with its X, Y, Z dimensions.
  3. Given that z-min is zero, the vehicle’s centerline is at y = 0, and the vehicle can be assumed to be symmetric about the Y plane, we can derive the Y and Z mins and maxes from this data. One way to find x-min is to use the RL Box creation tool.
  4. Click on the Mesh Controls tool > Box > Create Box Zone Around Body.
  5. Click on any surface of the body.
  6. From the Property Editor > Dimensions, set the Length to 4.07 (shown by the Measure tool).
  7. Orient your model to the Right view.
  8. Drag the box along X until the front and rear of the box appear to be just touching the front and rear surfaces of the model respectively.
  9. Note the x-min and x-max values in the Property Editor > Zone Extents.
  10. Delete the box by right-clicking on the part in the Model Browser > Mesh Controls.