eprintid: 18869 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/88/69 datestamp: 2024-06-04 14:11:18 lastmod: 2024-06-04 14:11:18 status_changed: 2024-06-04 14:04:19 type: article metadata_visibility: show creators_name: Lekkala, M.R. creators_name: Mohamed, L. creators_name: Jung, J.H. creators_name: Jin, C.K. creators_name: Li, B. creators_name: Jeong, B. creators_name: Kim, D.K. title: Numerical investigations of flow over wavy cylinders at sub-critical Reynolds number ispublished: pub keywords: Circular cylinders; Drag; Finite volume method; Flow control; Flow separation; Lift; Numerical methods; Offshore structures; Reynolds number; Vortex flow, Flow characteristic; Flow control methods; Flow-induced vibration; Force reductions; Large-eddy simulations; Passive flow control; Passive flow control method; Sub-critical; Vortex formation; Wavy cylinder, Large eddy simulation, comparative study; computer simulation; cylinder; design; flow control; flow field; fluid mechanics; fluid-structure interaction; large eddy simulation; numerical model; Reynolds number; vorticity note: cited By 2 abstract: Numerical study of three-dimensional unsteady flow behind the double wavy (DW), singe wavy (SW), and smooth circular (SC) cylinders geometry at subcritical Reynolds number (Re=3.0�103) using large-eddy simulations based on the finite volume method are investigated in this study. This study contributes to the understanding of the effects of geometric disturbances as a passive flow control method to reduce the hydrodynamic forces exerted by the fluid flow on the cylinders. The DW and SW cylinders with spanwise wavelength ratios as λ/Dm=3.79�6.82 and with fixed wave amplitude ratio as a/Dm=0.152 are investigated and compared with SC cylinder in terms of flow variables such as drag, lift coefficients, Strouhal number, vortex formation length, and vorticity contours of the cylinders. Furthermore, an investigation was also carried out to quantify the differences in the fluid flow properties behind SC and SW cylinders compared to DW cylinders. When compared to the SC and SW cylinders, the findings indicated that the DW cylinder reduces drag and lift coefficients significantly for every λ/Dm. A maximum reduction in fluid forces is observed at λ/Dm=6.06 for DW cylinder; 16.63 and 94.99 reduction in mean drag and lift fluctuations respectively compared to SC cylinder. The DW cylinder also showed a longer vortex formation length than SC and SW cylinders for every λ/Dm. The flow separation angle and mean streamwise velocity distributions are also investigated and compared between the SC, SW, and DW cylinders. The present study reveals that the geometric surface waviness of the cylinder can be used to minimize force coefficients at a sub-critical flow regime. The obtained conclusions could provide some references to the engineering field for the design stage of slender marine structures. © 2022 Elsevier Ltd date: 2023 official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85145834703&doi=10.1016%2fj.oceaneng.2022.113501&partnerID=40&md5=fff69a4d33895cc809b11219d1fb231f id_number: 10.1016/j.oceaneng.2022.113501 full_text_status: none publication: Ocean Engineering volume: 269 refereed: TRUE citation: Lekkala, M.R. and Mohamed, L. and Jung, J.H. and Jin, C.K. and Li, B. and Jeong, B. and Kim, D.K. (2023) Numerical investigations of flow over wavy cylinders at sub-critical Reynolds number. Ocean Engineering, 269.