International Journal of Frontiers in Engineering Technology, 2024, 6(4); doi: 10.25236/IJFET.2024.060413.
Dexin Liu1, Hongyuan Sun1, Qiang Xu2, Jin Miao1
1School of Naval Architecture and Port Engineering, Shandong Jiaotong University, Weihai, Shandong Province, 264209, China
2Yantai CIMC Raffles Ocean Engineering Co., Ltd., Yantai, 264670, China
This paper adopts the computational fluid dynamics (CFD) method, firstly compares with the classic experiment of Jauvtis and Williamson in 2004, and verifies the reliability of numerical simulation. Then the vortex-induced motion response of cylindrical structures with different ratios of natural frequencies of the in-line to the transverse natural frequency ratio (natural frequency ratio, f *=fnx/fny) is numerically simulated. Through research, it is found that the natural frequency ratio is an important parameter affecting the vortex-induced motion characteristics of cylindrical structures. With the increase of the natural frequency ratio f *, the response amplitude gradually increases and the cross-flow amplitude peak appears at a higher reduced speed, and the force-displacement curve undergoes a "phase switching" phenomenon; the change of the natural frequency ratio has little effect on the "locking" range of vortex-induced motion; at a specific reduced speed, the change of the natural frequency ratio will affect the vortex shedding mode, and the different vortex shedding modes that appear cause its motion trajectory to present an "8" shape with different tilt directions.
Vortex-induced vibration; natural frequency ratio; two-degree-of-freedom; fluid-structure interaction; trajectories
Dexin Liu, Hongyuan Sun, Qiang Xu, Jin Miao. Numerical simulation of cylinder under different natural frequency ratios. International Journal of Frontiers in Engineering Technology (2024), Vol. 6, Issue 4: 75-82. https://doi.org/10.25236/IJFET.2024.060413.
[1] Sarpkaya T. A critical review of the intrinsic nature of vortex-induced vibrations[J]. Journal of fluids and structures, 2004, 19(4): 389-447.
[2] Williamson C H K, Govardhan R. A brief review of recent results in vortex-induced vibrations[J]. Journal of Wind engineering and industrial Aerodynamics, 2008, 96(6-7): 713-735.
[3] Feng C C. The measurement of vortex induced effects in flow past stationary and oscillating circular and D-section cylinders[D]. University of British Columbia, 1968.
[4] Khalak A, Williamson C H K. Motions, forces and mode transitions in vortex-induced vibrations at low mass-damping[J]. Journal of fluids and Structures, 1999, 13(7-8): 813-851.
[5] Govardhan R, Williamson C H K. Modes of vortex formation and frequency response of a freely vibrating cylinder[J]. Journal of Fluid Mechanics, 2000, 420: 85-130.
[6] Dahl J M, Hover F S, Triantafyllou M S. Two-degree-of-freedom vortex-induced vibrations using a force assisted apparatus[J]. Journal of Fluids and Structures, 2006, 22(6-7): 807-818.
[7] Dahl J M, Hover F S, Triantafyllou M S, et al. Dual resonance in vortex-induced vibrations at subcritical and supercritical Reynolds numbers[J]. Journal of Fluid Mechanics, 2010, 643: 395-424.
[8] Zhao M. Effects of natural frequency ratio on vortex-induced vibration of a circular cylinder in steady flow[J]. Physics of Fluids, 2020, 32(7).
[9] KANG Z, JIA L S.An experiment study of a cylinder’s two degree of freedom VIV trajectories[J]. Ocean Engineering, 2013, 70:129-140.
[10] Jauvtis N, Williamson C H K. The effect of two degrees of freedom on vortex-induced vibration at low mass and damping[J]. Journal of Fluid Mechanics, 2004, 509: 23-62.