Abstract：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.
龚曙光，吴兴豪，谢桂兰，张建平. 无叶片风力机变固有频率系统的涡激摆动特性及捕能效率[J]. 振动与冲击, 2021, 40(19): 180-186.
GONG Shuguang, WU Xinghao, XIE Guilan, ZHANG Jianping. Vortex-induced swing characteristics and energy harvesting efficiency of bladeless wind turbine system with variable natural frequency. JOURNAL OF VIBRATION AND SHOCK, 2021, 40(19): 180-186.
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