Design and optimization of a marine current turbine: Effects of pitch angle and twist distribution

A 3 blade, 800 mm marine current turbine with 25° blade-pitch angle was numerically validated and modified to improve the turbine’s power coefficient using CFD and surrogate based optimization techniques. The pitch angle was varied from 15° to 30°. The twist distribution was varied along the blade span by an increment and decrement method. The twist was varied by a maximum of 95% increment/decrement with respect to its actual twist distribution. The combinations of all these designs were fed into in-house optimization code to find the optimal design point. A 13% increase in the power coefficient is reported.