GUO Tao, ZHANG Wen-hui, WANG Wen-quan, LUO Zhu-mei. EFFECTS OF HIGH MASS AND DAMPING RATIO ON VIV OF A CIRCULAR CYLINDER WITH LOW REYNOLDS NUMBER BASED ON IBM[J]. Engineering Mechanics, 2022, 39(3): 222-232. DOI: 10.6052/j.issn.1000-4750.2021.07.0566
Citation: GUO Tao, ZHANG Wen-hui, WANG Wen-quan, LUO Zhu-mei. EFFECTS OF HIGH MASS AND DAMPING RATIO ON VIV OF A CIRCULAR CYLINDER WITH LOW REYNOLDS NUMBER BASED ON IBM[J]. Engineering Mechanics, 2022, 39(3): 222-232. DOI: 10.6052/j.issn.1000-4750.2021.07.0566

EFFECTS OF HIGH MASS AND DAMPING RATIO ON VIV OF A CIRCULAR CYLINDER WITH LOW REYNOLDS NUMBER BASED ON IBM

  • The vibration problem of the high mass ratio system (the mass of structure is significantly larger than the mass of the surrounding fluid it displaces) is still prominent, as shown by the strong vibration event of Shenzhen SEG Plaza building under the action of low speed wind field. To investigate the high mass ratio effect on the vortex-induced vibration (VIV), the VIV of a circular cylinder supported by lightly damped springs and placed in a uniform flow at Reynolds number 80~150 with high mass ratio ( m^* = 14.8 \sim 280 ), damping ratio ( \zeta = 0.0012 \sim 0.036 ) and mass-damping ratio combination ( m^*\zeta ) is numerically simulated, and then analyzed using the sharp-interface immersed boundary method (IBM). The results show that: The accuracy and effectiveness of this method are verified through a comparison with literature and experimental results; In most of the high mass ratio cases, the “soft-lock-in” phenomena is observed when Re<100, which is the vortex-shedding frequency not matching the structural frequency exactly, and there is a slight detuning. The “lock-in” phenomena is observed for a range of Re=100~130. The resonance occurs when Re=110, the “lock-in” phenomena begins to disappear to structure when Re>130, and the “phase mutation” phenomenon appears between lift coefficients and cross-flow vibration amplitude; The high mass ratio plays an important role on VIV in the cases with same mass-damping ratio combination ( m^*\zeta ). The range of “lock-in” is wider, namely Re=90~140, e.g., the range of the system with mass ratio ( m^* = 14.8 ) is 1.67 times wider than the system with higher mass ratio ( m^* = 148 ); When resonance occurs, the vortex street mode is “2S” type, and the maximum cross-flow vibration amplitude is 0.5 times of the diameter of cylindrical also. In other words, the mass ratio has little effect on the amplitude. However, with the increase of damping ratio, the amplitude decreases gradually and the vibration is suppressed.
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