Drag and wake regime control of flow past tandem circular cylinders using hinged splitter plate: A numerical investigation

In the present numerical study, the drag and wake regime control of two-dimensional tandem identical circular cylinders (TCC) with a hinged splitter plate (HSP) at a Reynolds number of Re = 100 is investigated using the inhouse developed flexible forcing immersed boundary scheme-based one-step simplified lattice Boltzmann method. The gap G between the centres of the cylinders is set at G = 5.0D, where D is the diameter of the cylinder. The rigid splitter plate is hinged at the rear base point of the upstream cylinder, and it undergoes a sinusoidal pitching motion for the pitching amplitudes (θ_m) of 15º. In addition, the Strouhal number (St_f) and the splitter plate length (L_f) are varied between 0.1 – 0.4 and 0.0D – 1.0D, respectively. It is observed that the total drag of TCC with HSP configuration is always less compared to the stationary splitter plate of identical size. Moreover, the total drag of TCC-HSP arrangement decreases for increasing St_f at all L_f except when L_f = 1.0D, and a maximum of 35% drag reduction is achieved at St_f = 0.40 and L_f = 0.75D. However, beyond St_f ≥ 0.20, the total drag of TCC increases for L_f = 1.0D. The relationship between drag and the near wake flow structure will be thoroughly discussed in the presentation for varied St_f and L_f.