Supervisorer: Torben J. Larsen, DTU Vindenergi - Helge Aagaard Madsen, DTU Vindenergi - Gunner Chr. Larsen, DTU Vindenergi Uwe Schmidt Paulsen, DTU Vindenergi
Eksaminatorer: Ebba Delwick, DTU Vindenergi - Vasilis Riziotis, NTNU - Knud Kragh, Siemens Wind Power
Titel: Inflow Measurements from Blade-mounted Flow Sensors - Flow Analysis, Application and Aeroelactic Responce
Power and load performance of wind turbines are important for the development and continuous expansion of wind energy. The power and loads are highly dependent on the inflow conditions, which can be measured using different types of sensors mounted on nearby met masts, on the nacelle, at the spinner or at the blade.
To characterize the incoming turbulent wind flow that results in high and low fatigue loads, information about the temporal and spatial variations within the rotor area is required. This information can be obtained from a blade-mounted flow sensor, e.g. a five-hole pitot tube, which has been used in several research experiments over the last 30 years.
From its rotating position at the blade, a blade-mounted flow sensor is exposed to exactly the same inflow conditions as the turbine (including wake effects from upstream turbines). A blade-mounted flow sensor is able to provide valuable information about the instant inflow velocity as well as variations within the rotor plane, and that goes for all wind directions. The inflow, measured by a blade-mounted flow sensor, is, however, disturbed by the wind turbine. A method to compensate for this disturbance and estimate the free-stream inflow velocity has therefore been developed and utilised in this project.
Applications of measurements from blade-mounted flow sensors have been investigated. It is concluded that a blade-mounted flow sensor provides valuable information about the inflow. This information can be used for the control purposes and to investigate the complex relation between the inflow and the power and loads. Furthermore, the measurement can be used to characterise the inflow conditions that yield high loads and as input for aeroelastic simulations to improve the correlation between the measured and simulated loads.