The Wake of Three Square Prisms in Side-by-Side Arrangement

Abstract

The wake of three side-by-side square prisms placed normal to the oncoming flow at a Reynolds number Re = 150 is examined numerically using finite volume method. The prism center-to-center pitch L is varied from L/W = 1.1 to 9.0 where W is the prism width. Five distinct flow structures and their ranges are identified, viz., single-bluff-body flow (L/W 7.0). Physical aspects of each flow regime, such as vortex structures, gap flow deflections, shedding frequencies are discussed in detail. A secondary frequency other than the Strouhal number (primary frequency) is identified in symmetrically-biased and non-biased interlocked flow regimes. The origin and effect of the secondary frequency on lift forces are unearthed.