Crossflow induced vibrations of isosceles triangular cross-sections and related energy transfer at confined flow

Experimental investigations on cross-flow induced vibrations of rigid prisms with isosceles triangle cross-sections, elastically supported in a free-surface recirculating water channel at a large blockage ratio of 0.4, are presented. The experiments revealed that the oscillatory response differed markedly from that observed in unbounded flows. Notably, sustained oscillations at very low reduced velocities and pronounced hysteretic effects were observed. From an energy transfer perspective, the isosceles triangle with a vertex angle of 150°was identified as the optimal geometry, exhibiting superior efficiency in transferring flow energy compared to previously reported geometries.