Multi-objective optimization of blade profiles for a horizontal axis tidal turbine

A multi-objective optimization method for blade profiles of horizontal axis tidal turbines based on ISIGHT and BEM-CFD model was proposed in this paper. Firstly, the Bezier curve was applied to get the desirable pitch angle and the chord length distribution respectively which were determined by 8 control points. The sample points were extracted according to the Latin hypercube test design, and the objective functions of each sample point were obtained through BEM-CFD model. Then the fitting relationships between the eight variables and the two objective functions were established by applying the response surface method. At last the multi-objective optimization was executed through NSGA-II, and a final optimal solution was chosen from the Pareto frontier solution obtained from the optimization. It was demonstrated that the power coefficient of the turbine was improved by 0.96%, while the trust coefficient was reduced by 2.36%. The automatic multi-objective optimization for blade profiles was realized by introducing the Bezier curve and the BEM-CFD model to the optimization platform of ISIGHT and it can be applicable to engineering practice.