Wake Control of Flow Past Twin Cylinders via Small Cylinders

The drag and lift force of a twin-cylinder structure are often greater than those single cylinder, causing serious structural safety problems. However, there few studies on the passive control twin cylinders. study aimed to investigate performance reduction measures using small cylinders at Reynolds number 100. effects cylinder height (HD/D = 0~1.0, D is side length cylinder) cross-sectional shape fluid flow structures were studied by direct numerical simulations. mechanism was analyzed high-order dynamic mode decomposition (HODMD). results showed that significant occurred in co-shedding state, particularly when gap L/D 6.0. with HD 0.6, contrast, best reducing mean fluctuating It reduced upstream (UC) 2.58% downstream (DC) more 62.97%. coefficient for UC also decreased 70.41% (59.74%). hit under action cylinders, virtual missile-like aerodynamic formed leading edge UC. In this way, vortex consisted two asymmetric steady vortices significantly increased. This confirmed HODMD. coherence modes suppressed thus interaction between wake mitigated, which resulted reduction.