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The Orca3D Foil Wizard automates the process of creating foil-shaped surfaces, such as keels and rudders. The user selects the foil type, various dimensions, and options such as capping the tip or including a bulb, and the foil is automatically created.

In addition to the foil types that are contained in the program, you may enter your own foil offsets into a comma-separated value (.csv) file (normally done with Excel). A good source of offsets for a large number of airfoils is the University of Illinois website: http://www.ae.uiuc.edu/m-selig/ads/coord_database.html

A sample csv file is located in the installation directory, in a folder called "Sample Data." By default, this is c:\Program Files\Orca3D\Sample Data\AirfoilData.csv.

The format of the file is as follows:

For each foil there are two rows:

First row: family name, longitudinal offsets beginning at 1 (the trailing edge), decreasing to 0, then back up to 1

Second row: foil name, half-breadths for each longitudinal offset

For example, the data would look as follows in Excel (just the first 7 columns are shown; this particular foil has 52 columns)

To use the data, open the Foil Assistant, and click on Import CSV file. After the file is read, you should find your foils in the drop down lists of Foil Family and Foil Shape.

Clicking the Preview button will display the foil as you define the parameters.

If you want to include a bulb, go the the Bulb Design tab:

Bulbs are created by rotating an airfoil, and then "squishing" (scaling vertically). If the bulb will be manufactured from a different material then the keel, check "Make Bulb Separate Solid."

The sweep angle of the keel (phi) is defined at the reference chord location, which is the leading edge by default. In the Advanced Design tab, you can move the reference chord to a different location (0 is the leading edge, 1 is the trailing edge). You also have the option of specifying an elliptical planform.

The location of the foil may be specified by coordinates, with four options for the reference point. The foil may also be rotated or placed graphically.

The Analysis tab computes the volume and centroid of the foil, the bulb, and the combination. Making use of Orca3D's Weight/Cost functionality, the weight of the foil and bulb can be automatically computed, based on materials in the Material Library.

Once a foil has been created, it can be edited just like any other surface object in Rhino.