Module Documentation
Two classes are provided in the module: Polar and Airfoil. Generally, the Polar class is not needed for direct usage except for its constructor. All objects in this module are immutable. In other words, calling Airfoil.correct3D() creates a new modified airfoil object rather than editing the existing object.
Polar Class
A Polar object is meant to represent the variation in lift, drag, and pitching moment coefficient with angle of attack at a fixed Reynolds number. Generally, the methods of this class do not need to be used directly (other than the constructor), but rather are used by the Airfoil class.
Airfoil Class
An Airfoil object encapsulates the aerodynamic forces/moments of an airfoil as a function of angle of attack and Reynolds number. For wind turbine analysis, this class provides capabilities to apply 3-D rotational corrections to 2-D data using the Du-Selig method [DS98] for lift, and the Eggers method [EJCD03] for drag. Airfoil data can also be extrapolated to +/-180 degrees, using Viterna’s method [VJ82]. This class also adds methods to read and write AeroDyn airfoil files directly.
Z. Du and M. Selig. A 3-D stall-delay model for horizontal axis wind turbine performance prediction. In 1998 ASME Wind Energy Symposium, number AIAA-1998-21. Jan 1998.
A. J. Eggers Jr, K. Chaney, and R. Digumarthi. An assessment of approximate modeling of aerodynamic loads on the UAE rotor. In Aerospace Sciences Meeting and Exhibit, number AIAA-2003-0868. Jan 2003.
L.A. Viterna and D.C. Janetzke. Theoretical and experimental power from large horizontal-axis wind turbines. NASA TM-82944, National Aeronautics and Space Administration, Cleveland, OH. Lewis Research Center, September 1982.