Aerodynamic design methodology for wind tunnel tests of wind turbine rotors: Fid-Bau Portal

Aerodynamic design methodology for wind tunnel tests of wind turbine rotors

Bayati, Ilmas / Belloli, Marco / Bernini, Luca / Zasso, Alberto

AbstractThis paper illustrates the methodology and the experimental verification of the design of a 1/75 aero-elastic scaled rotor of the DTU 10 MW reference wind turbine for wind tunnel tests. The aerodynamic design was focused on the minimization of the difference, in terms of thrust coefficient, with respect to the full scale reference. From the Selig low-Reynolds airfoils database, the SD7032 one was chosen for this purpose and a corresponding constant section wing was tested at DTU red wind tunnel, providing force and distributed pressure coefficients for the design, in the Reynolds range $30 - 250 \times 10^{3}$ and for different angles of attack. The aero-elastic design algorithm was set to define the optimal spanwise thickness over chord ratio (t/c), the chord length and the twist, in order to match at least the first flapwise scaled natural frequency. An aluminium mould for the carbon fibre autoclave process was CNC manufactured based on B-Splines CAD definition of the external geometry given as an output of the design procedure. Wind tunnel tests at were carried out Politecnico di Milano on the whole 1/75 wind turbine scale model, confirming the successful aerodynamic design and manufacturing approaches. The experimental modal analysis carried out to verify the structural consistency of the scaled blade is also reported.

Highlights•Efficient aero-elastic optimal design of rotors for wind turbine scale models to be tested in wind tunnel experiments.•Aerodynamic design supported by analytical passages which are reported in the paper (literature about this topic is scarce).•Robust aerodynamic design approach also for different Reynolds numbers during wind tunnel tests compared to the design ones.•Aerodynamic and structural verification of the design, respectively through wind tunnel tests and experimental modal analysis.