Aerodynamic design of rotor blades
Introduction
Delft University has been involved in the design of rotor blades since the early nineties when Dutch blade manufacturer Aerpac launched its own first commercial product, the APX 40. The Section Wind Energy was responsible for the aerodynamic design of this 40m diameter stall controlled rotor.
Design tools
The rotor performance is calculated with a BEM-based code extended with a number of correction methods to account for deficiencies in the classical actuator disc model (effects of rotation and a heavy loaded rotor, for example).
At the start of a design process an optimization is initiated to search for rotor geometries with the highest possible energy yield with consideration of a number of prescribed rotor parameters. After this optimization, the blade chord and twist distributions need some further refinement.
Experience
In the airfoil design and test programs carried out by the IvW ample experience has been acquired concerning the effect of vortex generators , stall strips and Gurney flaps on the performance of different wind turbine airfoils.
Especially wind tunnel tests delivered valuable information to be used in calculations and tuning of rotor performance with stall strips and vortex generators installed. Most European commercial blades for stall controlled wind turbines use vortex generators of the type tested in the Delft wind tunnel on the 25% thick wind turbine airfoil DU 91-W2-250.
Rotor designs
Since the first design a number of years ago, Delft University has been involved in the aerodynamic design of rotor blades both on a national and on an international scale.
The Section Wind Energy has been responsible for -or involved in- the design of the entire range of APX rotor blades up to the latest APX70, a rotor blade suited for pitch controlled turbines with a rated power of 1.5 Megawatts. All Dutch rotor blade designs contain wind turbine dedicated DU (Delft University) airfoils.
Contact Information
Ruud van Rooij
tel: +31 (15) 278 1093,
R.P.J.O.M.vanRooij (add @tudelft.nl manually)
Nando Timmer
tel: +31 (15) 278 8279,
W.A.Timmer (add @tudelft.nl manually)
