Kilavuz, A.Durhasan, T.Ozgoren, M.Sarigiguzel, F.Sahin, B.Kavurmacioglu, L. A.Akilli, H.2025-01-062025-01-0620220948-42801437-821310.1007/s00773-022-00893-72-s2.0-85133889048https://doi.org/10.1007/s00773-022-00893-7https://hdl.handle.net/20.500.14669/1909In the present work, the flow topologies of a generalized torpedo-like geometry were investigated experimentally via Particle Image Velocimetry (PIV) and dye visualization. The study was conducted at length based on the Reynolds number of Re = 20 x 10(3) and 40 x 10(3). The torpedo-like geometry was positioned at ratios of immersion between 0.50 <= h/D <= 3.50 to investigate the free-surface effect on the present results, comparatively. PIV measurements provided ensemble-averaged velocity fluctuations, turbulent kinetic energy and Reynolds stress correlation with spectral analysis of the vortex-shedding mechanism. It is observed that different vortex shedding mechanism occurs depending on the immersion ratio. At h/D = 0.5, wake flow is characterized by the lower shear layer while upper shear layer dominates it at h/D = 0.75 and 1.00. The influence of the free-surface on flow characteristics is found to be negligible at h/D > 2.00 for both Reynolds numbers. Alternating vortex shedding occurs and the wake regions at h/D = 3.5 became nearly symmetrical. The size of the wake zone is moved closer to the stern of the torpedo-like geometry at Re = 40 x 10(3) and causes a smaller recirculating region. Spectral analysis of the streamwise velocity revealed a decreasing trend of Strouhal number with increasing immersion ratios. The changing of the Strouhal number showed a significant increase at h/D = 0.75 for Re = 20 x 10(3) an ever-decreasing trend for Re = 40 x 10(3).eninfo:eu-repo/semantics/closedAccessAUVFree-surfacePIVTorpedo-like geometryTurbulent flowArticle11473Q1113027WOS:000825067800001Q2