Reduction of fluid forces and vortex shedding frequency of a circular cylinder using rigid splitter plates

This study investigates the fluid forces acting on a circular cylinder in a laminar flow regime while using a passive control strategy. Three cases including the cylinder with one, two or three rigid splitter plates attached at its rear surface were considered and the location of horizontal plates (attachment angle) was varied between 0° and 90°. A comprehensive parametric study was performed to identify the optimum arrangement of the plates using the commercial finite element software, Comsol Multiphysics. The results show that the location and the number of the plates have crucial effects on the wake control. Increasing the number of splitter plates from one to two symmetric parallel plates led to a reduction in drag force, vortex shedding frequency and fluctuation of lift force. A maximum drag reduction of 23% for dual-splitters and 15% for single-splitter was achieved, at an angle of 45° at Reynolds number 100. However, increasing the number of attached plates to three didn’t have a significant effect on flow quantities when plates of the same length were utilised. The suitability of the third plate (the middle plate) was further studied by investigating the effect of length of the plate on flow quantities.