A novel passive flow control technique using circular arcs coupled with downstream splitters

The current study presents a novel piezoelectric design that converts vortex-induced vibrations caused by flow across a circular cylinder. This design can be implemented as a passive control method for energy harvesting. It encompasses the novelty of employing circular arc plates around a circular cylinder integrated with flexible splitters downstream. To assess the merits of the proposed design, a comprehensive parametric study for flexible splitters is conducted to specify the optimum layout of piezoelectric harvesters. The analysis is carried out at a low Reynolds number, Re=100, at which accurate non-intrusive experimental assessment of flow structure is difficult. The results indicate that the drag can be halved by adding circular arc plates to the cylinder. Moreover, it is demonstrated that the plate displacement increases by 18.29 folds for dual splitters compared with a single plate. By adding the arc plates, a further increase of 3.97 folds is obtained. Following this, the maximum strain with the inclusion of arc plates is 170.17% higher than the cylinder without arc plates (bare cylinder) for dual flexible splitters downstream, enhancing the energy harvesting performance remarkably. Finally, using the proposed design, the generated electrical power figures out at 3.13μW at 77.7% conversion efficiency.