Bladeless wind turbine captures wind energy through vortex-induced swing of its energy-capturing column. Here, a simplified dynamic model for 3D vortex-induced swing of the turbine system was established, and calculation formulas for natural frequency and energy harvesting efficiency of the turbine system were derived. Based on the nonlinear restoring torque function, the calculation formula for variable natural frequency of the turbine system was built. Based on verification of the established simplified model, effects of the variable natural frequency system on its swing characteristics and energy harvesting efficiency were further studied by using the computational fluid dynamics (CFD)-rigid body dynamics (RBD) coupled method. The results showed that slope of nonlinear restoring torque function controls variable natural frequency of the energy capturing system, the higher the level of nonlinearity, the faster the variation rate of natural frequency of the system; peak amplitude of swing and energy capture efficiency of the system decrease with increase in nonlinearity level of restoring torque, and the corresponding wind speed moves forward; selecting the appropriate variable natural frequency system can increase locking interval of main frequency and high swing amplitude interval; in process of vortex-induced swing, oblique vortex-shedding with different degrees occurs with height varying of energy-capturing column to have a certain effect on frequency locking of vortex-induced swing.
Key words
bladeless wind turbine /
vortex-induced swing /
variable natural frequency /
energy harvesting efficiency /
nonlinear recovery torque
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References
［1］赵兴强, 王军雷, 蔡骏,等. 基于风致振动效应的微型风能收集器研究现状［J］. 振动与冲击, 2017, 36(16):106-112.
ZHAO Xingqiang, WANG Junlei, CAI Jun, et al. A review on micro energy harvesters based wind induced vibration［J］. Journal of Vibration and Shock, 2017, 36(16): 106-112.
［2］BERNITSAS M M, 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, 2008, 130(4): 619-637.
［3］LEE J H, BERNITSAS M M. High-damping, high-Reynolds VIV tests for energy harnessing using the VIVACE converter［J］. Ocean Engineering, 2011, 38(16): 1697-1712.
［4］罗竹梅, 张立翔. 影响从涡激振动中获取能量的参数研究［J］. 振动与冲击, 2014, 33(9): 12-15.
LUO Zhumei, ZHANG Lixiang. Influence of parameters on extracting energy from a vortex-induced vibration［J］. Journal of Vibration and Shock, 2014, 33(9): 12-15.
［5］MACKOWSKI A W, WILLIAMSON C H K. An experimental investigation of vortex-induced vibration with nonlinear restoring forces［J］. Physics of Fluids, 2013, 25(8):087101.
［6］BARTON D A W, BURROW S G, CLARE L R. Energy harvesting from vibrations with a nonlinear oscillator［J］. Journal of Vibration and Acoustics, 2010, 132(2): 427-436.
［7］GAMMAITONI L, NERI I, VOCCA H. Nonlinear oscillators for vibration energy harvesting［J］. Applied Physics Letters, 2009, 94(16): 164102.
［8］YAZDI E A. Nonlinear model predictive control of a vortex-induced vibrations bladeless wind turbine［J］. Smart Materials and Structures, 2018, 27(7): 075005.
［9］黄明辉, 杨安全, 杨锋力. 一种磁轴承的两永磁环间磁作用力的计算［J］. 机械研究与应用, 2005, 18(1): 39-41.
HUANG Minghui, YANG Anquan, YANG Fengli. Calculation of for force between two permanent magnetic rings used in a hybrid magnetic bearing system［J］. Mechanical Research & Application, 2005, 18(1): 39-41.
［10］TAMIMI V, ZEINODDINI M, BAKHTIARI A, et al. 3D simulation of vortex shedding past tapered circular cylinders in subcritical reynolds numbers［C］∥ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. Rio de Janeiro： American Society of Mechanical Engineers, 2012.
［11］ACHENBACH E. Distribution of local pressure and skin friction around a circular cylinder in cross-flow up to Re=5×106［J］. Journal of Fluid Mechanics, 1968, 34(4): 625-639.
［12］WIESELSBERGER V C. Neuere festellungen über die gesetze des flüssigkeits un luftwiderstands［J］. Physikalische Ztschrift, 1921, 22: 321-328.
［13］NORBERG C. Fluctuating lift on a circular cylinder: review and new measurements［J］. Journal of Fluids and Structures, 2003, 17(1): 57-96.
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