Vortex-induced vibration and wake interference of two-degree-of-freedom elastically mounted elliptical cylinders in tandem at various spacing

Ocean Engineering, Год журнала: 2024, Номер 310, С. 118637 - 118637

Опубликована: Июль 8, 2024

Язык: Английский

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Transverse vortex-induced vibration of two elliptic cylinders in tandem: Effects of spacing

Physics of Fluids, Год журнала: 2023, Номер 35(11)

Опубликована: Ноя. 1, 2023

Renewable energy converters, such as bio-inspired fluttering foils, are gaining popularity due to their eco-friendly properties. However, the system with multiple objects has received scant attention. Here, we analyze how spacing influences transverse (one-degree-of-freedom) vortex-induced vibration of two tandem identical elliptic cylinders at a constant Reynolds number by employing wide range reduced velocities (Ur∈[2,14]) and space ratios (L∗∈[2,6]). The incompressible Navier–Stokes equations solved using overset mesh method in OpenFOAM® library. findings indicate that wake structure goes through eight distinct modes, well gap flow patterns (reattachment co-shedding). Vibrational responses, force parameters, determine three configurations. At small (L∗=2), upstream cylinder (UC) traditional lock-in (the frequency ratio fy/fn≃0.95–1.05) velocity (Ur≃7), downstream (DC) narrow region around Ur≃9. UC soft-lock-in synchronization fy/fn≃1.15) high (Ur≃8–10). vibrations both cylinders, but especially DC, reach relatively amplitudes. moderate (L∗=3), bears zone analogous single same mass ratio, while DC shows vast (Ur≃8–14). large (L∗=4, 5, 6), amplitude is often larger than when it region. exhibits peak Ur = 7 wake-galloping for > 12.

Язык: Английский

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Frequency lock-in mechanism in the presence of blockage effects

Physics of Fluids, Год журнала: 2024, Номер 36(7)

Опубликована: Июль 1, 2024

This study reveals the blockage effects on vortex shedding, lock-in mechanism of a forced oscillating cylinder, and coupling oscillation. The wind tunnel experiments large eddy simulations were conducted at Reynolds number 2000, encompassing range ratios from 0.15 to 0.5. cylinder is subjected harmonic oscillations in direction perpendicular incoming flow investigate frequency mechanism. research findings demonstrate that both vibration significantly influence dynamics shedding by altering development shear layer instability (SLI). For fixed high effectively suppresses growth transverse disturbances, promoting stable maintenance (SL). In blockage, deceleration induces separation boundary sidewalls subsequent constriction mainstream toward channel centerline, consequently leading an increase Strouhal number. case ratio, alters supplement near-SL region. During unlocked phase, significant occurrence backflow observed near SL, which promotes SLI. However, proper region, balance amount carried away mainstream, thereby suppressing backflow. are evident shift region triggering hysteresis, explained proposed mechanisms lock-in.

Язык: Английский

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Circular cylinders exposed to vortex-induced vibrations in restricted waters: VIV response from the bottom to the free surface

Applied Ocean Research, Год журнала: 2025, Номер 154, С. 104430 - 104430

Опубликована: Янв. 1, 2025

Язык: Английский

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Study of Reynolds Number Effects on Aerodynamic Forces and Vortex-Induced Vibration Characteristics of a Streamlined Box Girder

Applied Sciences, Год журнала: 2025, Номер 15(4), С. 2202 - 2202

Опубликована: Фев. 19, 2025

Due to the limitations of wind tunnel speed and size, achieving a model’s Reynolds number equal actual is challenging may lead discrepancies between experimental results. To investigate effects on aerodynamic forces vortex-induced vibration (VIV) characteristics streamlined box girder, tests were conducted study variations in surface pressures static main beam, as well VIV response time–frequency dynamic varied. The results indicate that tests, increases, drag coefficient beam decreases, lift slightly pitching moment remains almost unchanged. root mean square (RMS) values pressure coefficients show significant effect, with generally decreasing increases. In free onset increases from 14.35 m/s 16.03 m/s, maximum amplitude decreases 0.076 0.004, lock-in range narrows. RMS decrease. At some measurement points, dominant frequencies fluctuating spectra deviate corresponding frequency, correlation contribution local overall force (VIF) These changes explain reduction an increasing number. motion state has minimal effect their whereas it more coefficients.

Язык: Английский

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A review of flow-induced vibration in wind and oceanic flow: Mechanisms, applications, optimizations, and challenges

Ocean Engineering, Год журнала: 2025, Номер 325, С. 120748 - 120748

Опубликована: Март 3, 2025

Язык: Английский

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A deep modal model for reconstructing the VIV response of a flexible cylinder with sparse sensing data

Ocean Engineering, Год журнала: 2025, Номер 326, С. 120871 - 120871

Опубликована: Март 9, 2025

Язык: Английский

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A Contribution to the Temperature Particles Method—Implementation of a Large-Eddy Simulation (LES) Model for the Temperature Field

Applied Sciences, Год журнала: 2025, Номер 15(8), С. 4122 - 4122

Опубликована: Апрель 9, 2025

This paper introduces a numerical methodology for the investigation of two-dimensional, incompressible and unsteady flows. The analyses involve Fluid–Structure Interaction (FSI) over solid boundaries known shape with effects mixed convection heat transfer. main contribution is implementation Large-Eddy Simulation (LES) model energy equation. LES mathematical simulating turbulent Boussinesq approximation links vorticity transport equation to include buoyancy forces. consists discretizing field by using particles (computational points), which characterizes purely Lagrangian description. discretized Lamb discrete vortices (vortex blobs) temperature particles. velocity computed each particle as vortex cloud requires high computational cost. forces computation necessary blob because also Thus, all those computations involving interactions demand use parallel computing in OpenMP-Fortran. turbulence calculation makes second-order structure function model; that point during every time increment typical simulation. As examples application, two problems are chosen: nominally, flow around single circular cylinder interaction airplane wake ground plane. results compared experimental data, exhibiting very good agreement expected physics investigated problem.

Язык: Английский

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Experimental and numerical study on smoke bifurcation in L-shaped passage fire under stack effect

International Communications in Heat and Mass Transfer, Год журнала: 2025, Номер 165, С. 109075 - 109075

Опубликована: Май 14, 2025

Язык: Английский

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Vortex-induced vibration of the variable cross-sectional cylinder cases in transverse direction at Re = 3900 using OpenFOAM

Ocean Engineering, Год журнала: 2024, Номер 303, С. 117511 - 117511

Опубликована: Апрель 11, 2024

Язык: Английский

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