Blade–wake interactions in cross-flow turbines

This paper presents analytical bounds for blade–wake interaction phenomenon occurring in rotating cross-flow turbines for wind and tidal energy generation (e.g. H-rotors, Darrieus or vertical axis). Limiting cases are derived for one bladed turbines and extended to the more common three bladed configuration. Additionally, we present a classification of the blade–wake type of interactions in terms of limiting tip speed ratios.

These bounds are validated using a high order h/p Discontinuous Galerkin solver with sliding meshes. This computational method enables highly accurate flow solutions and shows that the analytical bounds correspond to limiting blade–wake interactions in fully resolved flow simulations.