l e a d

Downloaded Fnel. Field-testing was carried out for a 600 kW wind turbine rotor with Risø-A1 airfoils and two additional field tests are in progress on commercial megawatt sized rotors with Risø-P and Risø-B1 airfoils, respectively. The Risø-B1 airfoil family was designed for MW-size wind turbines with variable speed and pitch control. Key design objec-tives were twofold: ~1! To maximize the airfoil force coefficient contributing to rotor torque on a wind turbine in a specified design a-range. ~2! To have a high cl,max and a high design cl. Insensi-tivity of maximum lift to leading edge roughness was ensured by two additional design objectives: ~1! Having suction side transi-tion from laminar to turbulent flow in the leading edge region for angles of attack at cl,max. ~2! Obtaining a high cl,max with simu-lated leading edge roughness. Additional design objectives en-sured good geometric compatibility between the different airfoil sections and good geometric properties for inboard airfoils. The design was carried out with a Risø in-house multi disci-plinary optimization tool that has been developed since 199