Data Analysis from Experimental Measurements on a Vertical Axis Wind Turbine

This thesis presents the analysis of the data measured during the test campaign of a vertical axis wind turbine prototype developed by the company Nenuphar Wind in France. Three studies are presented: the study of the loads measured during the test campaign, the study of the vibrations, and the study of the stall conditions on the blades. Focus is put on the methodology of these analyses rather than on their detailed results. The preliminary processing of data is presented in more details, in particular the determination of selection levels asserting the quality of the data, an analysis of the drift of the zero of the loads sensor and an analysis of the cross-talk effects on the same loads sensors. With reference to the experience gained on previous prototypes, the quality of the data acquired on this prototype was greatly improved, allowing the use of stricter selection levels and a better quality of the results. The drift of the zero of the strain gauges was identified to be caused by temperature effects and was corrected on most of the sensors, leading to a significant decrease of the uncertainty on the loads measurements. The analysis of the cross-talks led to the implementation of a new and more precise way of calculation of the uncertainty due to these effects. Finally, the study of the dynamic stall on the blades of the new prototype developed by Nenuphar is described at the end of the report. The comparison with the previous prototype showed similar stall angular ranges, but less stalled rotations were observed on the new prototype than on the previous one.