Wind Loads on a Bottom-mounted Offshore Wind Turbine Tower in the Feathering Condition

Abstract

This paper describes the characteristics of wind loads on a bottom-mounted offshore wind turbine tower for a propeller-type wind turbine with three blades (Hub height: 80m, Rated power: 2.4MW) in the feathering condition. The wind loads based on field measurements were investigated using strain-gauge data. As a result, the maximum wind loads for the wind of the landside were bigger than those for the wind of the seaside under the influence of the land about 3 kilometers away from the wind turbine. The gust effect factors for the wind of the seaside were from 1.8 to 2.0 (=category of surface roughness I-II). Furthermore, the gust effect factors for the wind of the landside were more than 2.1 (=category of surface roughness III) in range of less than 30m/s.