Fast Aeroelastic Analysis and Optimisation of Large Mixed Materials Wind Turbine Blades

In this dissertation, structural wind turbine blade layouts are presented that are suitable for 10MW and 20MW wind turbine blades. This has been accomplished by using a medium fidelity static aeroelastic model embedded in an optimisation framework. The structural solutions are the result of a stiffness optimisation where the blade mass is minimised. To accomplish the structurally optimised blade, an aeroelastic analysis model is set up. This model consists of a nonlinear structural analysis module and an aerodynamic module. Both models are comparable in terms of the level of physical modelling and as such, it can be said that both models are of equal fidelity. This equal fidelity is favourable for the aeroelastic coupling between both models, which generates an aeroelastic solution that is accurate up to the level of physics present in the aerodynamic and the structural models...Aerospace Structures & Computational Mechanic

Comparison of wake models with data for offshore wind farms

A major objective of the ENDOW project is to evaluate the performance of wake models in offshore windfarm environments in order to ascertain the improvements required to enhance the prediction of power output within large offshore wind farms [1]. The strategy for achieving this is to compare the performance of the models in a wide range of conditions which are expected to be encountered during turbine operation offshore. Six models of varying complexity have been evaluated initially against the Vindeby single wake data in [2] where it was found that almost all of them overestimate the wake effects and also significant inconsistencies between the model predictions appeared in the near wake and turbulence intensity results. Based on the conclusions of that study, the ENDOW wake modeling groups have already implemented a number of modifications to their original models. In the present paper, new single wake results are presented against experimental data at Vindeby and Bockstigen wind farms. Clearly, some of the model discrepancies previously observed in Vindeby cases have been smoothed and overall the performance is improved. 1