Hydrodynamic independence and passive control application of twist and flapwise deformations of tidal turbine blades

The load-induced deformations experienced by axial-flow rotor blades can result in significant hydrodynamic impacts on operation. These changes hydrodynamics are dominated the flapwise and twist deformation components, affecting blade loading performance. This work uses blade-resolved computational fluid dynamics simulations to explore interactions of coupled deformations, their potential for use passive control strategies. were simulated under parametrically prescribed flapwise-only, twist-only flapwise–twist deformations. results show that effects adequately described blade-element theory regardless presence whereas induce local lift drag coefficients independent twist. For moderate deflections, generated two components be approximated from each other. observed independence between is used strategies a tidal rotor. By extrapolating an existing dataset containing CFD flapwise-only cases at different tip-speed ratios, paths designed within ratio, parameter space. demonstrate as alternative active pitch turbines, showing similar performance maximum loading, compared with strategy, over full cycle. In particular, it shown have important role power capping above rated flow speed.