One-way fluid-structure coupling of a cross-flow turbine in high confinement

Cross-flow turbines differ from conventional axial-flow turbines in that their axis of rotation is perpendicular to the direction of the flow. The geometry gives rise to a rectangular swept area that is more easily stacked in arrays to exploit the effects of confinement. This research explores the effect of confinement on turbines specifically in terms of the increased load on blades. Due to the high forces exerted on confinement-exploiting turbines, the blades undergo deformations in pitch and heave. These deformations can then interfere with the dynamic stall process, resulting in a coupled fluid-structure interaction. These dynamics are explored through a one-way fluid-structure interaction simulation. The deformations are computed through a non-deforming fluids simulation. These deformations are mapped to two-dimensional pitch and heave trajectories, which are then input back into the fluids solver to deduce the final changes in loads due to deformation. Simulations are computed for a pair of two-bladed turbines, and changes in performance and flow fields are reported. This research will help to determine allowable loads and deformations under high confinement configurations.