Abstract:Power coefficient and axial thrust coefficient are two important performance parameters of a marine current turbine. Thus a multi-objective optimization design method was proposed to optimize those coefficients for a horizontal-axis marine current turbine. Firstly, the pitch angle distribution curve of the turbine was parameterized by using a Bezier curve; and then the power coefficient and axial thrust coefficient were selected as the objective function, the levels of design factors were decided by the Box-Behnken experimental design method, and a 2nd polynomial relationship between the factors and the objective function was established by making use of response surface technology. At last, the turbine pitch angle curve was optimized by employing NSGA-II algorithm. In the optimization power coefficient and axial thrust coefficient were specified as the objective function, and the determined response surface was used as the individual fitness. It was demonstrated that the thrust coefficient was decreased by 2% and the power coefficient was increased by 0.4% for the optimized turbine. This confirmed the effectiveness of the optimization method proposed here.
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