A new method is proposed to estimate a floating wind turbine's annual energy production (AEP) using frequency and time-domain design techniques. The approach demonstrated herein estimates the AEP by performing a convolution between the floating platform response and the response power operators (RPOs) that map the average power produced by the turbine as a function of the amplitude and frequency of the platform motions. One advantage of this approach is that it can be performed early in the conceptual design phase to help discover design space trade-offs between the platform and rotor design. The methodology is applied to the IEA Wind 15 MW WindCrete spar-buoy model using OpenFAST. The RPOs are obtained by prescribing single-DOF platform motions to the turbine with a given amplitude and frequency. This methodology is then validated by comparing the AEP estimation from the RPOs with the AEP estimation from fully-coupled simulations. The results indicate that the method is able to estimate the value of AEP for a realistic sea-state and regular waves. However, further validation is needed as, in the first case, the turbine is moving too little and, in the second case, the contribution of the controller may be dominant.

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Accurate simulation of wind turbine wakes is critical for the optimization of turbine efficiency and prediction of fatigue loads. These wakes are three-dimensional, complex, unsteady and can evolve in geometrically complex environments. Modeling these flows calls thus for high-quality numerical methods that are able to capture and transport thin vortical structures on an unstructured grid. It is proposed here to assess the performances of a fourth-order finite-volume LES solver to perform massively parallel scale-resolving simulations of wind turbines wakes. In this framework, the actuator line method that takes the effect of the wind turbine blades on the flow into account is implemented. It is demonstrated that both near and far parts of the turbine wakes are accurately modeled as well as geometrical details. The methodology is assessed on two different test cases and validated with experimental results. It is demonstrated that the flow predictions are of equivalent quality on both structured and unstructured grids. The influence of the geometrical details (e.g. nacelle and tower) on the wake development as well as the influence of the discretization scheme are also investigated.@en