3D LES simulations of a static and vertically free-to-oscillate 4:1 rectangular cylinder: Effects of the grid resolution

Álvarez, A.; Nieto, Francisco Javier Fernández; Nguyen, Dinh Tung; Owen, J.S.; Hernández, Santiago

doi:10.1016/j.jweia.2019.06.012

Cited by 26 publications

(6 citation statements)

References 28 publications

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“…Moreover, the difference between the peak amplitudes obtained by the two turbulence models, can be explained as the k − ω SST models is an isotropic model, which does not resolve all the turbulent scales, concentrating them and yielding more energetic vortices, affecting the value of the aerodynamic damping. In order to account for the flow three dimensionality and resolution of different turbulent scales, LES simulations have been carried out in a different study, where it was found that the mesh discretisation, both in the spanwise direction and in the xy plane, plays a key role [27].…”

Section: Verification Study and Static Case Resultsmentioning

confidence: 99%

Study of a Static and Vertically Free-to-Oscillate 4:1 Rectangular Cylinder by Means of 2d Urans Simulations

Naveira

Nieto

Hernández

2018

Advances in Fluid Mechanics XII

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Flexible structures, such as cable-supported bridges, are prone to suffer from vortex-induced vibrations (VIV) under wind flow, as their span lengths are steadily growing in the last decades. VIV is a phenomenon that takes place at reduced wind speeds. The movements of the structure at VIV are selflimited and their frequency corresponds with the natural frequency of the structure (lock in). Therefore, VIV affects the structure's serviceability and can cause fatigue related damage. Hence, the need for identifying and avoiding this phenomenon at the early design stages is a key issue in long-span bridges design. In the present study a rectangular cylinder of width to depth ratio 4:1, which is a common simplification of a bridge deck cross section, is analysed for the static case as well as undergoing free vibration in the vertical direction under wind flow. These analyses have been carried out by 2D URANS CFD simulations, adopting two different turbulence models: the k − ω SST, which is based upon the Boussinesq eddy-viscosity approximation, and the Reynolds Stress Model, which directly calculates the components of the specific Reynolds stresses. For the static case the force coefficients, Strouhal number and the pressure coefficient distributions were calculated and compared with the available experimental data. In the case of the free-to-oscillate 4:1 rectangular cylinder, the oscillation amplitudes are compared with wind tunnel data reported in the literature. In addition, the frequencies and phase-lags between the time-dependent lift coefficient and the vertical oscillations are studied.

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Section: Verification Study and Static Case Resultsmentioning

confidence: 99%

Study of a Static and Vertically Free-to-Oscillate 4:1 Rectangular Cylinder by Means of 2d Urans Simulations

Naveira

Nieto

Hernández

2018

Advances in Fluid Mechanics XII

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“…It was suggested that eddies of an integral length scale exceeding this range might stimulate a significantly larger VIV amplitude. Similarly, Álvarez et al [80] also studied the VIV of a 4:1 rectangular cylinder using 3D LESs. They investigated the effects of the grid resolution on the VIV amplitudes determined from free oscillation simulations.…”

Section: (1) Investigations Of Factors That Affect Vivsmentioning

confidence: 99%

Wind-Induced Phenomena in Long-Span Cable-Supported Bridges: A Comparative Review of Wind Tunnel Tests and Computational Fluid Dynamics Modelling

2021

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Engineers, architects, planners and designers must carefully consider the effects of wind in their work. Due to their slender and flexible nature, long-span bridges can often experience vibrations due to the wind, and so the careful analysis of wind effects is paramount. Traditionally, wind tunnel tests have been the preferred method of conducting bridge wind analysis. In recent times, owing to improved computational power, computational fluid dynamics simulations are coming to the fore as viable means of analysing wind effects on bridges. The focus of this paper is on long-span cable-supported bridges. Wind issues in long-span cable-supported bridges can include flutter, vortex-induced vibrations and rain–wind-induced vibrations. This paper presents a state-of-the-art review of research on the use of wind tunnel tests and computational fluid dynamics modelling of these wind issues on long-span bridges.

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“…Different turbulence models, including the Unsteady Reynolds-Averaged Navier-Stokes Simulation (URANS), Detached Eddy Simulation (DES), and Large Eddy Simulation (LES), do not seem to reduce the dispersion in the results. Recent numerical simulation results imply that 3D LESs [6][7][8][20][21][22] or DESs [23][24][25][26][27] are more appropriate in complex three-dimensional flows around a rectangular cylinder. Nonetheless, Zhang [28] compared the performance of eight two-equation RANS models and two sub-grid scale (SGS) LES models in the unsteady flow around a finite cylinder with Re = 20,000.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Vortex Shedding from a 5:1 Rectangular Cylinder at Different Angles of Attack

Liu

Zhang

et al. 2022

JMSE

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Although flow around a 5:1 rectangular cylinder at small angles of attack (AoA) has been extensively studied, when the AoA becomes larger, the research is rare. Therefore, this study performs Unsteady Reynolds-Averaged Navier-Stokes simulations (URANS) using the k-ω SST turbulence model for unsteady flow around a two-dimensional 5:1 rectangular cylinder at different AoAs up to 45°. A strong dependence of the flow characteristics on AoA is observed through the analysis of the time-averaged lift coefficient, drag coefficient, and Strouhal number. The peak of lift and drag coefficient is observed to be correlated, respectively, to the leading- and trailing-edge vortex based on the analysis of the flow. The x′-directional length of the main recirculation bubble on the top side and the distance from the bubble center to the leading edge of the cylinder both reach the maximum when α = 15°. In addition, the standard deviation σx' of the time-averaged velocity U¯x' along the cylinder shows a trend of increasing at first and then decreasing, and that σy' also shows the same trend at α = 20°~45°; it fluctuates within a range of 0.05~0.2 at α = 0°~20°. Finally, two principal modes of vortex shedding are observed with α = 15° being their turning point, (i) “1 + 1” mode: in one vortex shedding period, two major vortices shed off from the top and bottom sides of the cylinder at α ≤ 15°; (ii) “2 + 2” mode, four vortices shed off from the top and bottom sides of the cylinder at α > 15° in one vortex shedding period.

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3D LES simulations of a static and vertically free-to-oscillate 4:1 rectangular cylinder: Effects of the grid resolution

Cited by 26 publications

References 28 publications

Study of a Static and Vertically Free-to-Oscillate 4:1 Rectangular Cylinder by Means of 2d Urans Simulations

Study of a Static and Vertically Free-to-Oscillate 4:1 Rectangular Cylinder by Means of 2d Urans Simulations

Wind-Induced Phenomena in Long-Span Cable-Supported Bridges: A Comparative Review of Wind Tunnel Tests and Computational Fluid Dynamics Modelling

Numerical Investigation of Vortex Shedding from a 5:1 Rectangular Cylinder at Different Angles of Attack

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