Strategy for the determination of unsteady aerodynamic forces on elongated bodies in grid-generated turbulent flow

Li, Ming; Li, Ming; Yang, Yang

doi:10.1016/j.expthermflusci.2019.109939

Cited by 36 publications

(6 citation statements)

References 33 publications

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“…approach for bridge buffeting analysis. However, with the progressive development of wind tunnel technology, some researchers (Larose, 2003;Li et al, 2020) have experimentally studied and found that the AAFs of blunt structures are significantly distinct from the Sears function, and it is not reasonable to use the Sears function directly as a transfer function in bridge buffeting analysis. To improve the accuracy of bridge buffeting analysis, the AAF should be calculated by wind tunnel tests (Ge and Zhao, 2014).…”

Section: Article History Abstractmentioning

confidence: 99%

Investigation of the 2D Aerodynamic Admittances of a Closed-Box Girder in Sinusoidal Flow Field

Zhang

et al. 2021

KSCE J Civ Eng

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This study investigates the aerodynamic admittances of a closed-box girder in both streamwise (u-) and vertical (w-) sinusoidal flow fields. A series of sinusoidal flows with discrete oscillation frequencies (f u = 0.2 − 1.2 Hz) and different oscillation amplitudes (Δu = 0.5 − 2.0 m/s) are experimentally generated, which are fully coherent in the span-wise direction. Meanwhile, the Computational Fluid Dynamics (CFD) method is utilized to simulate streamwise sinusoidal flows with higher frequencies (f u = 0.2 − 14 Hz). The u-turbulence-related two-dimensional aerodynamic admittance functions (2D AAFs) of the closed-box girder are identified frequency by frequency. On the other hand, the vertical sinusoidal flows are numerically simulated (f w = 0.2 − 14 Hz, Δw = 1.2 m/s), and the w-turbulence-related 2D AAFs are identified. Finally, the differences between u-, w-admittances and the equivalent ones are compared. The results indicate that u-and w-turbulence-related AAFs have different trends with the reduced frequency, and thus it is inaccurate to treat the contributions of u-and w-turbulence to admittances as equivalent in previous studies. Aerodynamic admittanceWind tunnel CFD Sinusoidal flows Closed-box girder CORRESPONDENCE Bo Wu

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Section: Article History Abstractmentioning

confidence: 99%

Investigation of the 2D Aerodynamic Admittances of a Closed-Box Girder in Sinusoidal Flow Field

Zhang

et al. 2021

KSCE J Civ Eng

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“…It can be referenced as bridge deck [23]. Several studies have been conducted with a focus on the spanwise correlation effects of vortex-induced forces in separate smooth and turbulent flow conditions [24][25][26]; the main consensus can be drawn as the greater the vibration amplitude, the more the correlation length, while the quantitative results are varying between amplitude, cross section, Reynolds number, etc. The non-dimensional vibration amplitude can be rewritten as:…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Comparison of Two-Dimensional and Three- Dimensional Responses for Vortex-Induced Vibrations of a Rectangular Prism

et al. 2020

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The accurate prediction of the amplitudes of vortex-induced vibrations (VIV) is important in wind-resistant design. Wind tunnel tests of scaled section models have been commonly used. However, the amplitude prediction processes were usually inaccurate because of insufficient evaluations of three-dimensional (3D) effects. This study presents experimental measurements of VIV responses in a prototype rectangular prism and its 1:1 two-dimensional section model in smooth flow. The results show that the section model vibrates with the same Reynolds number, equivalent mass, frequency, and damping ratio as those of the prototype prism without scale effects. The VIV amplitudes can be qualitatively and quantitatively measured and analyzed. The measured VIV lock-ins of these two models agree with each other. However, the prototype prism produces a 20% higher maximum amplitude than the section model. Several classical VIV mathematical models are used to validate the wind tunnel test results. This confirms that the 3D coupling effects of the modal shape and the imperfect correlations of excitation forces positively contribute to the maximum amplitude. Based on the section model outcomes, the amplified factor of 1.2 is found to be appropriate for the amplitude prediction of VIV for the present prism, and it can also provide a reference for other structures.

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“…Therefore, wind tunnel tests are generally conducted for the investigation of turbulence. At present, the simulation of turbulence is mainly dependent on traditional methods, such as spires and grilles, with respect to the average wind speed, turbulence intensity, and pulsating wind spectrum, among other parameters (Li et al, 2020;Ma et al, 2019;Ozono et al, 2007). The turbulence integral length scale represents the measurement of the average size of the turbulence vortices in the air flow (Wang et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the integral turbulence length scales in actual bridges are generally within several tens or hundreds of meters (Ma et al, 2019). The results of the studies conducted by Larose (1999) and Li et al (2020) on aerodynamic admittance under turbulence reveal that turbulent flow field simulations in the wind tunnels typically do not generate large-scale vortices, thus yielding low aerodynamic admittances in the lowfrequency band. Larose compared the flutter derivatives of the large-band East Bridge under passive grid turbulence and boundary layer turbulence, and found that the flutter derivatives of the two wind fields at the same turbulence intensities were significantly different, thus indicating that the turbulence integral length scale has a significant influence on the flutter derivatives.…”

Section: Introductionmentioning

confidence: 99%

Influence of turbulence integral length scale on aerostatic coefficients of bridge sections

Pei

Wang

et al. 2020

Advances in Structural Engineering

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This study investigates the influence of turbulence on the aerostatic coefficients of typical bridges by obtaining force measurements via the simulation of turbulence in wind tunnels. The traditional simulation method for turbulence based on spires and grilles cannot be employed for the accurate simulation of the large integral scale of turbulence in an actual wind field. Thus, in this study, the turbulence integral length scale was effectively increased using an active control grid. The wind fields of different turbulence integral scales were generated by controlling the vibration frequency of the active control grid. The aerostatic coefficients of five typical bridge sections (single-box girder, twin-box girder, truss girder, edge girder, and edge-box girder) were measured under turbulent and uniform flow. The test results were compared and analyzed, which revealed that the drag coefficients increased in accordance with a decrease in the reduced turbulence integral length scale, and they were lower under turbulent flow than under uniform flow.

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Strategy for the determination of unsteady aerodynamic forces on elongated bodies in grid-generated turbulent flow

Cited by 36 publications

References 33 publications

Investigation of the 2D Aerodynamic Admittances of a Closed-Box Girder in Sinusoidal Flow Field

Investigation of the 2D Aerodynamic Admittances of a Closed-Box Girder in Sinusoidal Flow Field

Comparison of Two-Dimensional and Three- Dimensional Responses for Vortex-Induced Vibrations of a Rectangular Prism

Influence of turbulence integral length scale on aerostatic coefficients of bridge sections

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