Flow-induced vibration of a square cylinder without and with interference

2006 ◽  
Vol 22 (3) ◽  
pp. 345-369 ◽  
Author(s):  
R. Ajith Kumar ◽  
B.H.L. Gowda
Keyword(s):  
Square Cylinder ◽  
Flow Induced Vibration

scholarly journals Energy harvesting from flow-induced vibration of a low-mass square cylinder with different incidence angles

AIP Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 025126
Author(s):  
Peng Han ◽  
Qiaogao Huang ◽  
Guang Pan ◽  
Wei Wang ◽  
Tianqi Zhang ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Square Cylinder ◽  
Flow Induced Vibration ◽  
Low Mass

scholarly journals FLOW INDUCED VIBRATION IN SQUARE CYLINDER OF VARIOUS ANGLES OF ATTACK

2022 ◽  
Vol 23 (1) ◽  
pp. 358-369
Author(s):  
Nur Ain Shafiza Ramzi ◽  
Kee Quen Lee ◽  
NUR AMIRA BALQIS MOHD ZAINURI ◽  
HOOI SIANG KANG ◽  
NOR’AZIZI OTHMAN ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Engineering ◽  
Kuala Lumpur ◽  
Velocity Range ◽  
Square Cylinder ◽  
Flow Induced Vibration ◽  
Rigid Cylinder ◽  
Square Cylinders

An experimental study was carried out to identify the effect of angle of attack on flow-induced vibration (FIV) of square cylinders. The experiment was conducted at the Aeronautical and Wind Engineering Laboratory (AEROLAB), UTM Kuala Lumpur using a wind tunnel that was free from external wind conditions. A supporting structure was designed and fabricated to conduct this experiment. The importance of this support structure was to enable the rigid cylinder to suspend and vibrate freely upon excitation of wind speed. The results were analysed through the response of amplitude and frequency of the rigid cylinder over a velocity range of 0.5m/s to 4.0m/s. The results showed that for a square cylinder of ?=0°, vortex-induced vibration (VIV) occurred at low reduced velocity (UR) in range of 5 ? UR ? 10 and galloping occurred at higher reduced velocity which started at UR=15. A tranquil zone was found between VIV and galloping in the reduced velocity range of 10 ? UR ? 15. As for ?=22.5° and 45°, only VIV response was found at low reduced velocity in range of 4? UR ? 9. ABSTRAK: Satu kajian eksperimentasi telah dilakukan bagi mengenal pasti pengaruh sudut serangan oleh getaran cetusan-aliran (FIV) dalam silinder persegi. Eksperimen ini dijalankan di Makmal Kejuruteraan Aeronautika dan Angin (AEROLAB), UTM Kuala Lumpur dengan menggunakan terowong angin yang bebas dari pengaruh angin luar. Struktur sokongan telah direka dan difabrikasi bagi tujuan eksperimen ini. Ini penting bagi membolehkan silinder pegun tergantung dan bergetar dengan bebas semasa ujian kelajuan angin. Dapatan kajian dianalisis melalui tindak balas amplitud dan frekuensi silinder pegun pada kadar halaju 0.5m/s sehingga 4.0m/s. Hasil kajian menunjukkan bahawa bagi silinder persegi ? = 0 °, getaran pengaruh-vorteks (VIV) berlaku pada halaju rendah (UR) dalam julat 5 ? UR ? 10 dan getaran lebih teruk telah ketara berlaku pada kadar halaju berkurang iaitu bermula pada UR = 15. Zon tenang dijumpai antara VIV dan getaran teruk pada kadar halaju berkurang 10 ? UR ? 15. Adapun pada ? = 22.5° dan 45°, hanya tindak balas VIV dijumpai pada halaju rendah dalam kadar 4? UR ? 9.

1001 Vibration controlling effect by T-shape fin installation on flow-induced vibration of square cylinder

2010 ◽  
Vol 2010 (0) ◽  
pp. 263-264
Author(s):  
Yusuke KAWABATA ◽  
Tsutomu TAKAHASHI ◽  
Mizuyasu KOIDE ◽  
Masataka SHIRAKASHI
Keyword(s):  
Square Cylinder ◽  
Flow Induced Vibration ◽  
Controlling Effect

There is no critical mass ratio for galloping of a square cylinder under flow

2021 ◽  
Vol 931 ◽  
Author(s):  
Peng Han ◽  
Emmanuel de Langre
Keyword(s):  
Critical Mass ◽  
Reduced Order Model ◽  
Mass Ratio ◽  
Square Cylinder ◽  
Order Model ◽  
Flow Induced Vibration ◽  
Reduced Order ◽  
Square Cylinders ◽  
Vortex Induced Vibrations ◽  
Low Mass

The flow-induced vibration of square cylinders under flow is known to be caused by two distinct mechanisms of interaction: vortex-induced vibrations and galloping. In the present paper we address the issue of the apparent suppression of galloping when the mass ratio between the solid and the fluid is low enough. By using a reduced-order model that we validate on pre-existing results, we show that galloping is actually not suppressed, but delayed to higher values of the flow velocity. This is explained using a linear stability analysis where the competition between unstable modes is related to the transition between vortex-induced vibration and galloping. Direct numerical simulations coupled with a moving square cylinder confirm that galloping can be found even at very low mass ratios.

Flow-Induced Vibrations of a Square Cylinder With Combined Translational and Rotational Oscillations

2016 ◽  
Author(s):  
T. P. Miyanawala ◽  
Mengzhao Guan ◽  
Rajeev K. Jaiman
Keyword(s):  
Incidence Angle ◽  
Translational Motion ◽  
Published Data ◽  
Square Cylinder ◽  
Flow Induced Vibration ◽  
Flow Induced Vibrations ◽  
3D Effects ◽  
Motion Parameters ◽  
Lock In ◽  
Rotational Oscillations

In this work, we investigate the combined translation and rotational flow-induced vibration (FIV) of elastically mounted square cylinder in a free-stream at zero incidence angle. We employ a partitioned iterative scheme to solve coupled fluid-rigid body interaction using unstructured grid. The fluid-solid coupled solver and the mesh is verified by investigating pure translational motion cases at zero incidence against published data for a laminar flow past a square cylinder. Further analysis revealed that the increase of mass ratio shifts the lock-in to higher reduced velocity region. The influence of of the torsional motion parameters is analyzed for a pure rotational case. The combined 3-DOF motion is next considered while keeping the above two analyses as reference. It was evident that, even small yaw vibrations adds circulation to the flow and thus increases the vortex intensity. This phenomenon is identified to be responsible for the differences of motion parameters between the isolated DOF cases and combined 3DOF cases. Finally, for the completeness of the study, the influence of 3D effects is estimated for the same geometry and also a high Re case is presented.

Downstream flat plate as the flow-induced vibration enhancer for energy harvesting

2017 ◽  
Vol 24 (16) ◽  
pp. 3555-3568 ◽  
Author(s):  
Nurshafinaz Mohd Maruai ◽  
Mohamed Sukri Mat Ali ◽  
Mohamad Hafiz Ismail ◽  
Sheikh Ahmad Zaki Shaikh Salim
Keyword(s):  
Flat Plate ◽  
Electrical Power ◽  
High Amplitude ◽  
Test Model ◽  
Square Cylinder ◽  
Flow Induced Vibration ◽  
Amplitude Response ◽  
Current Test ◽  
Wake Interference ◽  
Lower Magnitude

The prospect of harvesting energy from flow-induced vibration using an elastic square cylinder with a detached flat plate is experimentally investigated. The feasibility of flow-induced vibration to supply an adequate base excitation for micro-scale electrical power generation is assessed through a series of wind tunnel tests. The current test model of a single square cylinder is verified through a comparable pattern of vibration amplitude response with previous experimental study and two-dimensional numerical simulations based on the unsteady Reynolds averaged Navier–Stokes (URANS). In addition, a downstream flat plate is included in the wake of the square cylinder to study the effects of wake interference upon flow-induced vibration. A downstream flat plate is introduced as the passive vibration control to enhance the magnitude of flow-induced vibration and simultaneously increases the prospect of harvesting energy from the airflow. The study is conducted by varying the gap separation between the square cylinder and flat plate for 0.1≤ G/ D ≤3. The highest peak amplitude is observed for the gap G/ D = 1.2 with yrms/ D = 0.46 at UR = 17, which is expected to harvest ten times more energy than the single square cylinder. The high amplitude vibration response is sustained within a relatively broader range of lock-in synchronization. Meanwhile, for G/ D = 2 the vibration is suppressed, which leads to a lower magnitude of harvested energy. Contrarily, the amplitude response pattern for G/ D = 3 is in agreement with the single square cylinder. Hence, the flat plate has no significance to the wake interference of the square cylinder when the gap separation is beyond 3 D.

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