Objective THE AIM OF THE PRESENT PROJECT IS TO PROVIDE EXPERIMENTAL DATA THAT CAN QUANTIFY THE RELATIVE IMPORTANCE OF 3-DIM, UNSTEADY AND SCALE EFFECTS ON THE BLADE LOADS OF A HAWT ROTOR, OPERATING IN NATURAL CONDITIONS. THE APPROACH IS MEASUREMENTS ON A FULL-SCALE ROTATING BLADE OF LOCAL AERODYNAMICS FORCES AND THE RELATIVE FLOW VELOCITY VECTOR. ON BASIS OF SUCH MEASUREMENTS THE AIRFOIL COEFFICIENTS OF THE BLADE CAN BE FOUND AT DIFFERENT RADIAL STATIONS. DURING THE PAST YEAR AERODYNAMIC AND STRUCTURAL DYNAMICS MEASUREMENTS HAVE BEEN CARRIED OUT ON THE 19 M DIA. HAWT ON WICH ALSO THE ABOVE DESCRIBED LOCAL MEASUREMENTS OF FORCES AND FLOW WILL BE PERFORMED. THE MEASURED FLAPWISE BENDING MOMENTS AT 5 RADIAL STATIONS ON THE BLADE INDICATE THAT THE AIRFOIL CHARACTERISTICS OF THE ROTATING BLADE DIFFER CONSIDERABLY FROM 2D DATA. HOWEVER, THE INFLUENCE OF 3-DIM FLOW AND UNSTEADY FLOW ON THESE DEVIATIONS HAVE STILL TO BE QUANTIFIED. MEASUREMENTS ON THE REBUILT BLADE WITH THREE BLADE SEGMENTS FOR LOCAL MEASUREMENTS OF AERODYNAMICS FORCES CAN HOPEFULLY CONTRIBUTE TO THIS. THE FINAL INSTRUMENTATION AND CALIBRATION OF THIS BLADE IS NOW CARRIED OUT AND IN MARCH 1989 IT WILL BE MOUNTED ON THE TURBINE. Experimental studies of the aerodynamics of the main mechanisms controlling the aerodynamic forces on a rotating horizontal axis wind turbine (HAWT) blade have been made. In particular, the importance of 3-dimensional flow effects, unsteady effects and rotary wing effects were quantified. The present work dealt, mainly, with the dynamic response of the turbine, and data on the aerodynamic load input and the transfer function between load input and response were also of interest. The experimental setup comprised a 100 kW stall regulated turbine with a 19 m rotor and which is operated at 2 fixed rotational speeds. The power spectrum of the aerodynamic load input (derived on the basis of measured angle of attack and relative velocity and a linear approximation of the Cn against a curve) and the power spectrum of the flapwise response minus the inertia force component were in good agreement at low wind speeds. However, at high wind speeds, the standard deviation of the response is 50 to 100 % higher than the standard deviation of the load input. Stall hysteresis is probably the main cause of this discrepancy. Fields of science engineering and technologyenvironmental engineeringenergy and fuelsrenewable energywind powerengineering and technologymechanical engineeringvehicle engineeringaerospace engineeringaeronautical engineering Programme(s) FP1-ENNONUC 3C - Research and development programme (EEC) in the field of Non-Nuclear Energy, 1985-1988 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator RISOE NATIONAL LABORATORY EU contribution No data Address Frederiksborgvej 399 ROSKILDE Denmark See on map Total cost No data Participants (2) Sort alphabetically Sort by EU Contribution Expand all Collapse all CRANFIELD UNIVERSITY United Kingdom EU contribution No data Address Road Wharley End MK43 0AL CRANFIELD,BEDFORD See on map Links Website Opens in new window Total cost No data Central Electricity Generating Board (CEGB) United Kingdom EU contribution No data Address London See on map Total cost No data
