Durhasan, Tahir2025-01-062025-01-0620200029-801810.1016/j.oceaneng.2020.1075182-s2.0-85085019912https://doi.org/10.1016/j.oceaneng.2020.107518https://hdl.handle.net/20.500.14669/2215Flow patterns downstream of the hollow square cylinder with slots are experimentally investigated to show effect of the slot ratio on the wake flow characteristics and turbulence statistics at Reynolds number of Re = 6000 using the particle image velocimetry (PIV) technique. Proper orthogonal decomposition (POD) analyses indicate that the self-issuing jet dramatically changes the mechanism of vortex shedding interaction. Penetration of the self-issuing jet into the wake region leads to increasing of the vortex formation length for low slot ratios. On the other hand, the self-issuing jet penetrates further downstream due to increasing momentum coefficient of the jet and splits the wake region in half for high slot ratios. Strouhal number increases with the increasing slot ratio and it attains approximately the twofold of the solid cylinder case, since the self-issuing jet accelerates the vortex shedding process. However, turbulence statistics are significantly reduced for all slot ratios. Distributions of the spectral density in the wake region of the cylinder indicate that the vortex shedding instability could be reduced considerably by the slotted cylinder. Drag coefficient, which is estimated from PIV data, reduces up to 42% in comparison with the solid cylinder model.eninfo:eu-repo/semantics/closedAccessDecomposition of the spectral analysisEstimated drag coefficientFlow topologyPIVPODSlotted hollow square cylinderArticleQ1209WOS:000542188700029Q1