| dc.description.abstract | This work presents a linearized model of a floating wind turbine using the semi-submersible OOStar base geometry, a 10MW turbine and automation of the potential flow coefficients computation. It is associated with a design optimization problem which minimizes the cost of the platform w.r.t. two hull-shape geometric variables. Constraints based on international standards, limiting the maximum motion, stress and fatigue response are applied. A comparison with state-of-the-art non linear simulations showed that the response to waves is rather accurate but the response to wind needs to be improved for above-rated wind speeds. The linear model is however acceptable for capturing trends in the system's dynamics and is therefore suited for early design stage calculation. Eventually, the model is used to explore the design space manually, and identify optimization trends. The decrease in the columns' diameter is limited by the resulting drop in pitch restoring and by the pitch natural frequency getting too close to the wind excitation range. Decreasing the pontoon length drives the heave frequency dangerously close to the wave frequencies. | |
