Wind Turbine Airfoils and Rotor Wakes - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 384

Figure 6-6. Common wind turbine airfoils, designed originally for aircraft.
(a) NACA 23012 (b) NACA 4415 (c) NACA 63-215 (d) NASA LS(1)-0413 Modified (e)
NACA 0015

-- a stable C L, max at stall, despite blade fouling

-- larger lift-to-drag ratios

-- limited C L, max at outboard sections, for control of peak power in high winds

As we noted previously, the numerous different demands made of airfoil sections along
the span of a wind turbine blade preclude the possibility of the design of a single airfoil
which might be “ideal” in all senses. However, if a limited class of wind turbines is
defined, it then becomes possible to specify airfoil requirements for the rotors of this class.
The spanwise variation in requirements may be accounted for by specifying different lift
and drag properties (and consequently different airfoil sections) at different radial locations.
The definition of a rotor class provides us with input for which rotor performance codes
may be run, so that the relative performance with different airfoil sections may be
calculated and evaluated. Airfoil contours are shaped to produce the desired flow
characteristics at selected radial stations using analysis tools such as the Eppler code [Eppler
and Somers 1980], an early computational fluid dynamics (CFD) code.