A constrained optimisation process for the design of tidal turbine blades with experimental validation

This paper presents a way of conceptualizing the design of rotor blades for tidal turbines. The method uses systems principles and attempts to highlight the need to design the rotor within the context of other system components, rather than pursuing the goal of optimizing design point performance in isolation. The method begins by assuming that the axial induction factor is a primary design variable rather than it being fixed at a value of 1/3. Example geometries are presented from this method, as are their performance characteristics. It is shown that blades designed in this way can exhibit thrust characteristics that are significantly different from a rotor designed to operate at an induction factor of 1/3 (one example shows a 68% decrease in runaway thrust). Furthermore, experimental work was undertaken designed to confirm these differences in performance characteristics. Results show very good correlation with predictions.