Comparative analysis of the flow control over a circular cylinder with detached flexible and rigid splitter plates

Abstract

A comparative study is performed on a circular cylinder with both flexible and rigid splitter plates (SPs). This study has the novelty of using single and dual detached SPs located downstream of the cylinder. The dimensionless gap distance between the first splitter plate and the cylinder as well as the distance between the SPs are varied. The strain of flexible SPs can be used for energy harvesting from the flow. Therefore, a parametric study is performed to find the optimal design for placing piezoelectric polymers. The two-dimensional fluid–structure-interaction analysis is performed based on the arbitrary Lagrangian–Eulerian scheme using COMSOL Multiphysics. Flow characteristics quantities, tip amplitude, and strain are evaluated at different arrangements of the SPs. The results reveal that wake control enhances effectively by doubling the number of SPs. Strain assessments indicate that the strain of dual SPs increases by more than 100% compared to the single plate case. In addition, the amplitude of the dual SPs increases by a remarkable ratio of 18.29 compared to the single plate. In the case of rigid and flexible SPs at a certain arrangement, dramatic reductions of 97.8% and 76.35% in the Strouhal number are obtained compared to a bare cylinder. In addition, 18% drag reduction compared to the bare cylinder is recorded for the rigid SPs. The presented passive method can be used as an attractive approach in flow control as well as energy harvesting from ocean waves and sea currents.