FreeCAD Memo

How to create an airfoil

9/22/2013
Version 0.13
In this example, we create 3D airfoil from cross-sectional shape of airfoil. For example, shape as shown in following figures can be created.
Screwed Airfoil
Scaled Airfoil

Creating a basic shape

  1. In this example, we import a cross-sectional airfoil shape of NACA0012(Download) into FreeCAD and create a 3D shape from it.
    Drag&Drop the file "NACA0012.dat" into FreeCAD window. Whena dialog as shown in a following figure is displayed, select "Common airfoil data(importAirfoilDAT)" to import the data.
    Import dat
    NACA0012 Profile
  2. Switch a workbench to Draft workbench. Select "DWire" in the parts tree and apply DowngradeDraft_Downgrade twice to convert it to a wire.
  3. Select "Wire" in the parts tree and apply CloneDraft_Clone to copy the wire. After coping, select "Colone of wire" in the parts tree and enter 2.0 into [Placement]-[Position]-[z] at Property Data tab.
    ComboView Clone
  4. Switch a workbench to Part workbench and create a solid from two wires with Loft toolPart_Loft.
    ComboView Loft
  5. Now 3D airfoil is created. It is bit difficult to check shapes in default display mode. So select the "Loft" in the parts tree and set [Display Mode] in [View] tab of the property.to [Shaded] mode.
    ComboView Shaded
    NACA0012 Solid

Twisting the airfoil

In parts tree, select [Clone Of Wire] under the [Loft] and set following parameters at [Clone Of Wire]'s properties to twist airfoil with 45 degrees around the Z-axis passing through the origin.
  • Angle : 45.00
  • Axis : [0.00 0.00 1.00]
ComboView Screw
Screwed Airfoil

Changing the width of airfoil

In parts tree, select [Clone Of Wire] under the [Loft] and set following parameters at [Clone Of Wire]'s properties to change the size of cross-section shape to 1/2 at the airfoil tip.
  • Scale : [0.50 0.50 1.00]
ComboView Scale
Scaled Airfoil
Note:
It is possible to create more complex shape of airfoil by using three or more cross-section shapes in a similar way.
References: