Controlled dynamic analysis of offshore wind turbines under random environmental conditions-An experimental investigations

Abstract

Offshore wind turbines are used now-a-days to tap and convert the wind speed to electrical energy. Recent developments include installation of wind turbines in offshore seas. Monopiles, Tripods and 3- or 4-legged jacket platforms are largely used for mounting the turbine. This paper deals with the experimental analysis of an offshore wind turbine mounted over a fixed jacket platform. A 4-legged platform is currently used for the present study. Finite element methods are used for the numerical analysis of the Jacket. Code to code comparison of the results is studied to finalize the structure. A scaled down model of a steel jacket is fabricated. A scaled down model of a wind turbine is mounted on top of the jacket. The jacket and the turbine act as an integral unit. Any force or momentum acting on the turbine is transferred to the jacket and vice versa. The whole setup is installed in a wave basin capable of generating regular and random waves. The wave basin is of the size 30m length by 30m width with a water depth of 3.0m. Flap type wave generator is located at one end for wave generation and absorbers are installed on the side ends for absorbing the waves to prevent the reflection. The forces and moments acting on the structure under various loading conditions are reported. The results include the variation of the forces acting at the base of the jacket support structure with respect to the variation in different wave parameters.