![]() ![]() Improving Bending Moment Measurements on Wind Turbine BladesĭOE Office of Scientific and Technical Information (OSTI.GOV)įull-scale fatigue testing of wind turbine blades is conducted using resonance test techniques where the blade plus additional masses is excited at its first resonance frequency to achieve the target loading amplitude. The method is shown to be quite robust to the type of experimental problems that could be expected to occur in the testing of full-scale and model-scale rotors. Good agreement between the predicted and the measured airloads was found up to 0.90 R, but the agreement degraded towards the blade tip. The method was validated by comparing the calculated airload distribution with the original wind tunnel measurements which were made using ten modes and twenty measurement stations. In this procedure, the blade rotation in vacuum modes is calculated, and the airloads are expressed as an algebraic sum of the mode shapes, modal amplitudes, mass distribution, and frequency properties. ![]() This paper presents a method for the estimation of blade airloads, based on the measurements of flap bending moments. The effects of the number of measurements, the number of modes, and errors in the measurements and the blade properties are examined, and the method is shown to be robust. ![]() ![]() The estimated airloads are compared with the wind tunnel measurements. The application of the method is examined using simulated flap bending moment data that have been calculated for measured airloads for a full-scale rotor in a wind tunnel. The modal amplitudes are identified from the blade bending moments using the Strain Pattern Analysis Method. The blade's rotation is calculated in vacuum modes and the airloads are then expressed as an algebraic sum of the mode shapes, modal amplitudes, mass distribution, and frequency properties. Estimation of blade airloads from rotor blade bending momentsĪ method is developed to estimate the blade normal airloads by using measured flap bending moments that is, the rotor blade is used as a force balance. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |