Blade element momentum (BEM) theory is the backbone of many industry-standard aerodynamic models. However, the analysis of floating offshore wind turbines (FOWTs) introduces new challenges, which could put BEM models to the test. This study systematically compares four aerodynamic models, ranging from BEM to computational fluid dynamics, in an attempt to shed light on the unsteady aerodynamic phenomena that are at stake in FOWTs and whether BEM is able to model them appropriately.

This study investigates the offshore wind turbine support structure’s fatigue life by a rapid numerical model which considers the effects of scour and a tuned mass damper. An optimization technique is proposed to find the damper's optimal parameters, considering time-varying scour. It is found that the damper optimized by the proposed optimization technique performs better than an initially designed damper in terms of fatigue life enhancement.

We used desktop studies, geographic information system mapping, modeling and environmental impact assessment techniques to identify optimal offshore wind cable routes for a proposed offshore wind energy area off the coast of North Carolina by navigating around sensitive or hazardous seabed areas.  Similar methods can be adopted by other offshore industries during early planning phases to improve consenting; reduce costs; and, importantly, minimize impacts on marine environments. 

This paper introduces the multi-scale coupled (MSC) model, an engineering framework aimed at modeling turbine–wake and wind farm–gravity wave interactions, as well as local and global blockage effects. Comparisons against large eddy simulations show that the MSC model offers a valid contribution towards advancing our understanding of the coupled wind farm–atmosphere interaction, helping refining power estimation methodologies for existing and future wind farm sites.

Tropical cyclone winds are challenging for wind turbines. We analyze a tropical cyclone before landfall in a mesoscale model. The simulated wind speeds and storm structure are sensitive to the boundary parametrization. However, independent of the boundary layer parametrization, the median change in wind speed and wind direction with height is small relative to wind turbine design standards. Strong spatial organization of wind shear and veer along the rainbands may increase wind turbine loads.

This study presents results from a wind tunnel experiment on a model wind turbine. Using a non-intrusive measurement technique, the flow around the turbine blades was measured. In post-processing, the blade-level aerodynamics are derived from the measured flow fields. The detailed experimental database has great value in validating numerical tools of varying complexity, which aim at simulating wind turbine aerodynamics as accurately as possible.

Experiments offer incredible value to science, but results must come with an uncertainty quantification to be meaningful. We present a method to simulate a proposed experiment, calculate uncertainties, and determine the measurement duration (total time of measurements) and the experiment duration (total time to collect the required measurement data when including condition variability and time when measurement is not occurring) required to produce statistically significant and converged results.

For a few years now, various techniques have been studied to maximize the energy production of a wind farm, that is, from a system consisting of several wind turbines. These wind farm controller techniques are often analyzed individually and can generate loads higher than the design ones on the individual wind turbine. In this paper we study the simultaneous use of two different techniques with the goal of finding the optimal combination that at the same time preserves the design loads.

Movable surfaces on wind turbine (WT) blades, called active flaps, can reduce the cost of wind energy. However, they still need extensive testing. This study shows that the computer model used to design a WT with flaps aligns well with measurements obtained from a 3month test on a commercial WT featuring a prototype flap. Particularly during flap actuation, there were minimal differences between simulated and measured data. These findings assure the reliability of WT designs incorporating flaps.

Wind turbines influence each other, and these wake effects limit the power production of downstream turbines. Controlling turbines collectively and not individually can limit such effects. We experimentally investigate a control strategy increasing mixing in the wake. We want to see the potential of this so-called Helix control for power optimization and understand the flow physics. Our study shows that the control technique leads to clearly faster wake recovery and thus higher power production.

Rotary airborne wind energy (RAWE) machines transform wind energy into electric energy by transmitting the mechanical torque produced on a rotor to a generator on the ground by using its own structure, which is a spinning helix. Having a good understanding of the behavior of the helix is crucial in the design of RAWE machines. This work presents a theoretical model to simulate the helix’s dynamics and experimental tests to characterize it.