Ispir, M.Goktepeli, I.Aksoy, M. H.2026-03-102026-03-1020261735-35721735-3645https://doi.org/10.47176/jafm.19.4.3976https://hdl.handle.net/20.500.13091/13049Experimental rotation effects on flow past cylinders have been observed. The cylinders have the porous media coatings (PMC) named PMC1, PMC2, PMC3 and PMC4. For the range of rotation rates, including alpha = 0.52, alpha = 1.05 and alpha = 1.57, the flow characteristics have been presented at a Reynolds number of Re = 2500. In comparison with the experimental results for stationary cases (alpha = 0), the zones with lower streamwise velocity values became closer to the bodies as the rotation rates were enhanced. The maximum wake displacements have been obtained as 1.8D for the circular cylinder with no coating. For coated cylinders, these are 1.9D, 1.9D, 1.7D and 1.95D for the PMC1, PMC2, PMC3 and PMC4, respectively. For the same reason, the cross-stream velocity components also approached the circular cylinders. However, asymmetrical distributions for flow patterns have been attained. For this reason, the lower values for cross-stream velocity became more dominant in the wake. Moreover, separated flows were obviously seen by velocity fluctuations. The interaction of separated and wake flows induced these fluctuations. Wake lengths have been reduced compared to those of the cases with no rotation. The highest percentage for wake length reduction has been obtained as 92.9% by alpha = 1.05 for the bare cylinder. The maximum reductions have been attained as 89.7% by alpha = 1.05 for PMC1, 96.3% by alpha = 1.05 for PMC2, 85.7% by alpha = 1.57 for PMC3 and 90% by alpha = 1.05 for PMC4. The experimental results have also been presented for turbulence values. The highest turbulence kinetic energy value, 0.236, has been obtained at alpha = 1.05 for the bare cylinder. These values are 0.271 at alpha = 0.52 for the PMC1, 0.271 at alpha = 1.05 for PMC2, 0.245 at alpha = 1.05 for the PMC3 and 0.217 at alpha = 0.52 for the PMC4. As with the flow patterns, the induction by surface coating has been clearly observed through the augmentation of alpha values. Since surface movement for coating has also been seen for these situations, boundary layer thickness values have been reduced.eninfo:eu-repo/semantics/openAccessFlow ControlParticle Image Velocimetry (PIV)Porous Media Coated CylinderReynolds NumberRotation RateArticle10.47176/jafm.19.4.39762-s2.0-105029765458