Novel design of rotary pontoon floating wind turbine reliability assessment by self-deconvolution method

Abstract

As the offshore wind energy industrial sector develops dynamically towards its economic viability targets, it is important to continuously improve structural design, while increasing energy output and minimizing operational repair downtime. Large horizontal-axis wind turbines (HAWTs) are already commonplace and they are in the process of being designed on a larger scale, which is challenging. Vertical-axis wind turbines (VAWTs), where the tilt of the axis of rotation is not a concern, constitute an alternative to HAWTs in the field of for floating offshore wind turbines design. This case study presents hydrodynamic loads analysis and structural failure risk assessment for the novel offshore cross-flow vertical axis Wind Energy Marine Unit (WEMU) with a large floating rotor design. The primary goal of this research was to assess the structural operational reliability of the novel WEMU design, given realistic environmental conditions. Environmental wave loads acting on the torus of the semi-submersible pontoon during its rotation had been modeled numerically. Subsequently, structural risk failure was assessed, utilizing a state-of-the-art self-deconvolution extrapolation scheme. Reliability prognostic results had been cross-validated versus the existing four-parameter Weibull fit method. To summarize, the presented case study combines a novel structural design with a recently developed reliability method. The latter can be of practical engineering use for contemporary floating wind turbine design.