| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1718061 | Aerospace Science and Technology | 2014 | 16 Pages |
Numerically simulated results are presented for shear flow past a square cylinder (of height a) near a wall (at a gap height 0.5a) in presence of eddy promoting rectangular cylinders (of fixed height a with different widths b⩽ab⩽a) to gain a better insight into the dependency of aerodynamic characteristics of both the cylinders on the parameters: spacing distance between the cylinders S (=D/a:0.5⩽S⩽20=D/a:0.5⩽S⩽20) and aspect ratio r (=b/a:0.1⩽r⩽1.0=b/a:0.1⩽r⩽1.0). The value of Reynolds number Re is kept as Re=100 and 200Re=100 and 200. The governing unsteady Navier–Stokes equations are solved numerically based on the finite volume method on a staggered grid system using QUICK scheme. The resulting equations are then solved by an implicit, time-marching, pressure correction-based SIMPLE algorithm. The influence of numerical parameters on the validated code used in this study is demonstrated here. The strong dependency of vortex shedding (from both the cylinders) on aspect ratio r and spacing distance S are explored and, hence, a region of finite area in the Sr-plane is proposed in order to generate the unsteadiness in the steady flow of the downstream cylinder. An attempt is made to identify the different flow regimes depending on the flow patterns of the downstream cylinder, associated with the geometrical parameters (S and r). Owing to the differences in the basic shedding frequency of the square (downstream) cylinder from that of the rectangular cylinder (promoter) of different widths, the major issue of appearing multiple peaks in the spectrum of fluctuating lift coefficient of the downstream cylinder is addressed. The thrust force observed on the downstream cylinder in presence of the thinner promoter at closely spaced arrangement is justified presenting the surface pressure distribution. Finally, the present numerical results at large spacing distances are certified with some previous numerical and experimental findings.
