Force Measurements on a VAWT Blade in Parked Conditions
Division of Electricity, Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala, Sweden
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Energies 2017, 10(12), 1954; https://doi.org/10.3390/en10121954
Received: 24 October 2017 / Revised: 17 November 2017 / Accepted: 20 November 2017 / Published: 24 November 2017
(This article belongs to the Collection Wind Turbines)
The forces on a turbine at extreme wind conditions when the turbine is parked is one of the most important design cases for the survivability of a turbine. In this work, the forces on a blade and its support arms have been measured on a 12 kW straight-bladed vertical axis wind turbine at an open site. Two cases are tested: one during electrical braking of the turbine, which allows it to rotate slowly, and one with the turbine mechanically fixed with the leading edge of the blade facing the main wind direction. The force variations with respect to wind direction are investigated, and it is seen that significant variations in forces depend on the wind direction. The measurements show that for the fixed case, when subjected to the same wind speed, the forces are lower when the blade faces the wind direction. The results also show that due to the lower forces at this particular wind direction, the average forces for the fixed blade are notably lower. Hence, it is possible to reduce the forces on a turbine blade, simply by taking the dominating wind direction into account when the turbine is parked. The measurements also show that a positive torque is generated from the blade for most wind directions, which causes the turbine to rotate in the electrically-braked case. These rotations will cause increased fatigue loads on the turbine blade.
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Keywords:
extreme loads; vertical axis wind turbine; parking; measurements
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MDPI and ACS Style
Goude, A.; Rossander, M. Force Measurements on a VAWT Blade in Parked Conditions. Energies 2017, 10, 1954. https://doi.org/10.3390/en10121954
AMA Style
Goude A, Rossander M. Force Measurements on a VAWT Blade in Parked Conditions. Energies. 2017; 10(12):1954. https://doi.org/10.3390/en10121954
Chicago/Turabian StyleGoude, Anders; Rossander, Morgan. 2017. "Force Measurements on a VAWT Blade in Parked Conditions" Energies 10, no. 12: 1954. https://doi.org/10.3390/en10121954
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