Experimental Investigation on Flow Induced Motion of an Equilateral Triangle Prism

PDF(1566 KB)

Journal of Vibration and Shock ›› 2016, Vol. 35 ›› Issue (20) : 17-23.

ZHANG Jun LIAN Ji-jian LIU Fang XU Guo-bin YAN Xiang

Author information +

History +

Abstract

According to typical experiments of flow induced motion (FIM) of a circular cylinder, a series of FIM experiments for an equilateral triangle prism elastically mounted in water channel are performed with different system stiffness. The responses of the amplitude and frequency of the prism, along with its frequency spectrum features and wake flow mode, are expounded. Besides, the influence of the system stiffness on the FIM and the wake flow mode is discussed. The test results indicate that the FIM of the prism can be divided into three primary regions: the vortex induced vibration (VIV) branch, the transition branch from VIV to galloping and the galloping branch. Significant FIM response of an equilateral triangle prism on springs develops in an infinite range of flow velocities and without a self-limited response. The transition branch is initiated accompanied with a steep increase in amplitude and a precipitous drop in frequency. The frequency presents “lock-in” phenomenon in the VIV upper branch and the galloping branch. The system stiffness changes the wake flow mode of the prism at the same reduced velocity thus affecting the amplitude and frequency responses. The maximum amplitude ratio for the prism reaches 2.11, which is higher than the maximum amplitude ratio 1.90 for a single circular cylinder. Compared with a circular cylinder, an equilateral triangle prism is more beneficial to improving energy extraction from the flow with low velocity.

Key words

equilateral triangle prism / flow induced vibration / galloping / wake flow mode / system stiffness

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

ZHANG Jun LIAN Ji-jian LIU Fang XU Guo-bin YAN Xiang. Experimental Investigation on Flow Induced Motion of an Equilateral Triangle Prism[J]. Journal of Vibration and Shock, 2016, 35(20): 17-23

References

[1] Blevins RD. Flow-Induced Vibration [M]. New York: Van Nostrand Reinhold, 1990.
[2] 管青海, 李加武, 胡兆同, 等. 栏杆对典型桥梁断面涡激振动的影响研究[J]. 振动与冲击, 2014, 33 (3): 150-156.
GUAN Qing-hai, Li Jia-wu, HU Zhao-tong, et al. Effects of railings on vortex-induced vibration of a bridge deck section [J]. Journal of Vibration and Shock, 2014, 33 (3): 150-156.
[3] 高云, 任铁, 付世晓, 等. 柔性立管涡激振动响应特性试验研究 [J]. 振动与冲击, 2015, 34 (17): 6-11.
Gao Yun, Ren tie, Fu Shi-xiao, et al. Experimental study on response characteristics of VIV of a flexible riser [J]. Journal of Vibration and Shock, 2015, 34 (17): 6-11.
[4] Bernitsas MM, Raghavan K., Ben-Simon Y, et al. VIVACE (vortex induced vibration aquatic clean energy): A new concept in generation of clean and renewable energy from fluid flow [J]. Journal of offshore mechanics and arctic engineering-transactions of ASME, 2008, 130(4): 041101-15.
[5] Bernitsas MM, Ben-Simon Y, Raghavan K. The VIVACE converter: model tests at high damping and Reynolds number around 105 [J]. Journal of offshore mechanics and arctic engineering-transactions of ASME, 2009, 131: 011102.
[6] Feng CC. The measurement of vortex induced effects in flow past stationary and oscillating circular and d-section cylinders [D]. Vancouver: University of British Columbia, 1968.
[7] Khalak A, Williamson CHK. Fluid forces and dynamics of a hydroelastic structure with very low mass and damping [J]. Journal of Fluids and Structures, 1997, 11(8): 973-982.
[8] Williamson CHK, Roshko A. Vortex formation in the wake of an oscillating cylinder [J]. Journal of Fluids and Structures, 1988, 2: 355-81.
[9] Raghavan K, Bernitsas MM. Experimental investigation of Reynolds number effect on vortex induced vibration of rigid circular cylinder on elastic supports [J]. Ocean Engineering 2011, 38 (5-6): 719-731.
[10] Alonso G, J Meseguer, I Pérez-Grande. Galloping instabilities of two dimensional triangular cross-section bodies [J]. Experiments in Fluids, 2005, 38:789–95.
[11] Alonso G, Meseguer J. A parametric study of the galloping stability of two dimensional triangular cross-section bodies [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2006, 94:241-53.
[12] Alonso G, Meseguer J, Pérez-Grande I. Galloping stability of triangular cross sectional bodies: a systematic approach [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2007, 95:928-40.
[13] Iungo GV, Buresti G. Experimental investigation on the aerodynamic loads and wake flow features of low aspect-ratio triangular prisms at different wind directions [J]. Journal of Fluids and Structures, 2009, 25:1119-35.
[14] Camarri S, Salvetti MV, Buresti G. Large-eddy simulation of the flow around a triangular prism with moderate aspect-ratio [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2006, 94:309-322.
[15] 徐枫, 欧进萍, 肖仪清. 不同截面形状柱体流致振动的CFD 数值模拟[J]. 工程力学, 2009, 26(4): 7-15.
XU Feng, OU Jin-ping, XIAO Yi-qing. CFD numerical simulation of flow-induced vibration with different cross section cylinder [J]. Engineering Mechanics, 2009, 26(4): 7-15.
[16] Ding L, Zhang L, Wu CM, et al. Flow induced motion and energy harvesting of bluff bodies with different cross sections [J]. Energy Conversion and Management, 2015, 91: 416-426.
[17] 丁林, 张力, 姜德义. 高雷诺数范围内不同形状柱体流致振动特性研究 [J]. 振动与冲击, 2015, 34(12): 176-181.
DING Lin, ZHANG Li, JIANG De-yi. Research on the Flow-induced Motion of Bluff Body with Different Cross Sections at High Reynolds Number [J]. Journal of Vibration and Shock, 2015, 34(12): 176-181.
[18] Morse TL, Govardhan RN, Williamson CHK. The effect of end conditions on the vortex-induced vibration of cylinders [J]. Journal of Fluids and Structures, 2008, 24(8): 1227-1239.
[19] Nemes A, Zhao J, Jacono D, et al. The interaction between flow induced vibration mechanisms of a square cylinder with varying angles of attack [J]. Journal of Fluid Mechanics, 2012, 710:102-30.
[20] Davis JT. Velocity characteristics in the wake of an oscillating cylinder [D]. Cambridge: Massachusetts Institute of Technology, 2001.
[21] Hover FS, Davis JT, Triantafyllou MS. Three-dimensionality of mode transition in vortex-induced vibrations of a circular cylinder [J]. European Journal of Mechanics, B/Fluids, 2004, 23(1):29-40.