1 Wind Energy Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2 Risø National Laboratory for Sustainable Energy, Technical University of Denmark3 Department of Wind Energy, Technical University of Denmark4 unknown
For modern rotor blades with their very large aspect ratio, the blade tip is a very limited part of the overall rotor, and as such of limited importance for the overall aerodynamics of the rotor. Even though they may not be very important for the overallpower production, the tip noise can be very important for the acoustics of the rotor , and the blade tips can as well be important for the aerodynamic damping properties of the rotor blades . Unfortunately, not many options exists for predictingthe aerodynamic behavior of blade tips using computational methods. Experimentally it is di±cult to perform detailed measurements in the form of pressure and velocity measurements in natural wind conditions on modern large scale turbines due to theinherent unsteadiness in the natural wind. The present study describes the application of four different Navier-Stokes solvers to tip shape studies, and shows that these codes are well suited to study the flow around different tip shape geometries, andcan predict the pressure distributions at the blade tip quite accurately.