Passive control of vortex-induced vibration by spanwise grooves

Law, Yun Zhi; Jaiman, Rajeev K.

doi:10.1016/j.jfluidstructs.2018.08.004

Cited by 43 publications

(6 citation statements)

References 30 publications

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“…The first strategy, modifying the flow field to control VIV from the perspective of flow stability, is a commonly used method by fluid mechanics researchers. The most direct approach is to modify the surface shape of the structure such as by introducing roughness (Gao et al 2015;Jiang et al 2023), grooves (Lim & Lee 2002;Huang 2011;Law & Jaiman 2018), shroundings (Kumar et al 2018) and so on. However, this approach may have limited effects on VIV control, as it often results in relatively small disturbances to the flow field and insignificant changes to the stability characteristics of the flow.…”

Section: Control Of Vivmentioning

confidence: 99%

Elimination of lock-in phenomenon in vortex-induced vibration by passive modal control

Luo,

Gao,

Lyu

et al. 2024

J. Fluid Mech.

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Theoretical analysis and numerical results have shown that frequency lock-in in vortex-induced vibration (VIV) is caused by the instability of the structural mode rather than a resonant response to external excitations. However, there is a lack of experimental evidence supporting relevant theoretical research findings. This study investigates VIV suppression with a passive modal controller (PMC) for a circular cylinder at Reynolds numbers $Re = 60$ and $Re = 40$ , using experiments to distinguish the effects of stable and unstable wake modes. Comparative analysis before and after the implementation of the PMC reveals significant reduction in the vibration amplitude and the disappearance of the lock-in phenomenon at $Re = 60$ . The vibration frequency closely follows the vortex shedding frequency after control, while dynamic mode decomposition of the flow field indicates that the wake mode is dominant. For $Re = 40$ , the vibration is eliminated and the flow becomes steady. Additionally, the root loci of the coupled system are investigated before and after the PMC implementation via linear stability analysis. The results indicate that the PMC can alter the dynamic characteristics of the original system, causing the structural mode and PMC mode to couple when approaching the PMC frequency. Then, the interaction typically improves the stability of the structural mode. Finally, a parametric study is conducted in the experiment, as well as a linear stability analysis. The study provides experimental evidence that stability control of the structural mode is the key to suppressing VIV and eliminating the lock-in phenomenon.

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Section: Control Of Vivmentioning

confidence: 99%

Elimination of lock-in phenomenon in vortex-induced vibration by passive modal control

Luo,

Gao,

Lyu

et al. 2024

J. Fluid Mech.

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“…To further understand the flow field, a PIV visualization of the flow field of the cylindrical spreading (Law and Jaiman 2018) structure was performed in this study. Figure 8 compares the timeaveraged streamlines and time-averaged velocities for a smooth cylinder at y/D = 0 in the (x, z) plane and secondary grooved cylinders with different depths.…”

Section: Time-averaged Streamlines and Velocity Fieldmentioning

confidence: 99%

Experimental Study on Wake Characteristics of Secondary Grooved Cylinders with Different Depths

2023

JAFM

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In this study, the flow field of a new secondary-grooved cylinder is determined by using particle image velocimetry (PIV) to understand the wake characteristics at different depths of the secondary grooved cylinders. In order to analyze the wake characteristic behind the secondary grooved cylinder with different depths, time-averaged streamlines, time-averaged velocity, RMS velocity, Reynolds stress, turbulent kinetic energy, and instantaneous flow structures are employed. The recirculation zone for secondary grooved cylinders with different depths decreases when compared to the smooth cylinder; the peak magnitudes of flow velocity fluctuation intensity and transverse velocity fluctuation intensity for secondary grooved cylinders with different depths are reduced and the locations appear delayed. Furthermore, in contrast to the smooth cylinder, the secondary grooved cylinders with different depths' Reynolds stress and turbulent kinetic energy are increased by the wake flow, and the transient large-scale vortex is split into several smaller-scale vortices behind the secondary grooved cylinders. The results obtained for the above flow structure are more significant when h/D = 0.05 for the secondary grooved cylinder.

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“…Salah satu cara yang bisa digunakan adalah dengan memodifikasi bentuk geometri saluran. Cara ini merupakan metode pasif untuk mengontrol terbentuknya vortex [6]. Bentuk-bentuk geometri yang berasal dari alam mampu menjadi contoh dan memberikan inspirasi dalam mencari desain saluran yang lebih baik.…”

Section: Pendahuluanunclassified

“…Alur pada pipa berperan menjaga pergerakan fluida untuk tetap mengalir dengan kondisi yang lebih terarah [6,7]. Keberadaan alur mampu mengurangi total tegangan geser sepanjang permukaan [16].…”

Section: Gambar 6 Ilustrasi Vortex Pada Pipa Beralurunclassified

Pressure Drop dan Pola Aliran Dua Fase (Air-Udara) Melewati Pipa Groove Vertikal

Aji

Widhiyanuriyawan

Yuliati

2020

JRM

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This research was conducted to observe the effect of adding grooves in the two-phase flow of water-air in the same direction through a vertical pipe to changes in pressure and fluid flow patterns. Test section in the form of pipes with grooves made of acrylic material with a length of 100 cm and an internal diameter of 2.54 cm. The geometric shape of the acrylic pipe is modified by giving a groove in the direction of the pipe along the test section. Grooves used amounted to 4 and 16 and pipes without grooves used as a comparison. Tests are carried out by flowing water and air that has been mixed through the inlet side upward. The ratio of air velocity to water velocity (VG / VL ) is 0.24-1.13. The method used in this study is experimental. Retrieval of pressure drops data is done by using a differential pressure transmitter. Visual observations are also made using a DSLR camera equipped with a flash and video observations using a smartphone with slow-motion mode. The results showed changes in flow patterns and pressure drop values. Slugs in pipes with grooves disappear faster and pressure drops are lower than pipes without grooves.

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Passive control of vortex-induced vibration by spanwise grooves

Cited by 43 publications

References 30 publications

Elimination of lock-in phenomenon in vortex-induced vibration by passive modal control

Elimination of lock-in phenomenon in vortex-induced vibration by passive modal control

Experimental Study on Wake Characteristics of Secondary Grooved Cylinders with Different Depths

Pressure Drop dan Pola Aliran Dua Fase (Air-Udara) Melewati Pipa Groove Vertikal

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