Wake-induced vibration suppression for a circular cylinder using a pair of jets

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(6)

Published: June 1, 2024

The wake-induced vibration (WIV) presents significant challenges to the structural integrity of multi-cylinder configurations. To effectively alleviate this problem, a numerical simulation is conducted assess effect an active control technique that uses two jets located at shoulder region cylinder suppress WIV in two-degree-of-freedom. equations motion for response are solved using Newmark-β method. method employed solve governing response. Three kinds angular position (β) on suppression investigated detail, including 30°, 60°, and 90°. β defined as angle between injection horizontal line. When maximum cross-flow amplitude ratio (CFAR) reduced from 0.9 (uncontrolled) 0.5 (β = 30°), reduction approximately 44%. On contrary, CFARs remain 1.0 case 3 60°) 4 90°). Especially 4, showed galloping after upper branch region. Since positioned shoulders, vortexes caused by opposite main induced cylinder. As consequence, shred wake cylinder, which leads driving force reduction. Therefore, cylinder's significantly suppressed.

Language: Английский

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Flow-induced vibrations of a square cylinder at different angles of attack: The importance of the in-line vibrations

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

A square cylinder is an ideal geometry for investigating both vortex-induced vibration (VIV) and galloping instabilities. The present work aims to evaluate the significance of in-line freedom on flow-induced vibrations (FIVs) a subjected flow. Numerical simulations were conducted two-degree-of-freedom (2-DOF) one-degree-of-freedom (1-DOF) with different angles attack. mass ratio, which structural divided by displaced fluid mass, set 5, Reynolds number fixed at 200. Detailed comparisons amplitude responses, frequency hydrodynamic characteristics, forces, transitions VIV-galloping, vortex shedding modes 2-DOF one only cross-flow oscillation conducted. Overall, trend 1-DOF similar that cylinder. However, when α between 5° 20°, results show there are two obvious peak regions in response cylinder, while second region not found This indicates considering crucial FIV as can alter responses vibrations.

Language: Английский

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Numerical investigation on the suppression of vortex-induced vibration system by assembling different rotors based on quasi-active control method

Ocean Engineering, Journal Year: 2024, Volume and Issue: 311, P. 119015 - 119015

Published: Aug. 19, 2024

Language: Английский

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Experimental investigation on energy conversion and vortex-induced vibration suppression of marine risers with turbine-type external devices

Energy, Journal Year: 2024, Volume and Issue: unknown, P. 134155 - 134155

Published: Dec. 1, 2024

Language: Английский

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