A review of numerical modelling and optimisation of the floating support structure for offshore wind turbines

Abstract

Compared to onshore wind power, floating offshore wind power is a promising renewable energy source due to higher wind speeds and larger suitable available areas. However, costs are still too high compared to onshore wind power. In general, the economic viability of offshore wind technology decreases with greater water depth and distance from shore. Floating wind platforms are more competitive compared to fixed offshore structures above a certain water depth, but there is still great variety and no clear design convergence. Therefore, optimisation of the floating support structure in the preliminary phase of the design process is still of great importance, often up to personal experience and sensibility. It is fundamental that a suitable optimisation approach is chosen to obtain meaningful results at early development stages. This review provides a comparative overview of the methods, numerical tools and optimisation approaches that can be used with respect to the conceptual design of the support structure for Floating offshore wind turbines (FOWT) attempting to detail the limitations preventing the convergence to an optimal floating support structure. This work is intended to be as a reference for any researcher and developer that would like to optimise the support platform for FOWT.

Development of a floating Vertical Axis Wind Turbine for the Mediterranean Sea

“…To evaluate the performances and to quantify the advantages previously introduced, it is essential to use numerical models with different levels of accuracy and computational time required. Several review works on numerical models are available in the literature [2], [3]. However, many state-of-theart software, only allow to simulate HAWTs due to greater diffusion and technological maturity.…”

The importance of aeroelasticity in estimating multiaxial fatigue behaviour of large floating offshore wind turbine blades

“…Thanks to higher and smoother wind power availability, as well as lower environmental and visual constraints, offshore wind turbines are typically larger than onshore [2] : in Europe, the average rated power of installed turbines in 2020 was 7.5 MW. The trend is to manufacture even larger wind turbines, in order to reduce the impact of installation and maintenance costs [1] .…”

“…OpenFAST offers three different aeroelastic modelling options, including rigid body, modal analysis with flapwise and edgewise deflection, and geometrical exact beam theory (GEBT) as implemented in the Beamdyn submodule [28] . Alternative software options, such as HAWC2, Orcaflex, or Bladed, can be utilized in place of Openfast [2] . As an example, HAWC2 employs a distinct approach to aeroelastic models compared to Openfast, notably incorporating the Timoshenko beam, which is not available in OpenFAST.…”

A Review of Numerical and Physical Methods for Analyzing the Coupled Hydro–Aero–Structural Dynamics of Floating Wind Turbine Systems

“…Among these floating concepts, the semi-submersible platform, stabilized mainly by buoyancy, is a promising technology and is the most explored technology compared to the others. This is due to the applicability of these platforms in different water depths, their good hydrodynamic performance, and facility in the installation process [3,5,6].…”