ScholarWorks@중앙대학교

초록

This study presents an efficient electromagnetic wind energy harvester based on wake-interference rotational galloping, a novel flow-induced vibration mechanism designed to enhance aerodynamic-to-electrical energy conversion. The proposed system integrates a symmetric T-shaped bluff body and a downstream interference body to induce self-excited rotational motion, enabling continuous electromagnetic power generation even under low wind speeds. This multi-stage strategy represents a systematic and iterative optimization process in which each stage builds upon the previous ones, with experimental validation and theoretical modeling being integrated to enhance overall performance. The optimal configuration—comprising a 35 mm interference body, 45 mm spacing, and 25 mm coil distance—achieves a stable rotational limit cycle at a critical wind speed of 4.8 m/s and delivers a maximum average power of 7.26 mW at 10 m/s. A theoretical model based on the extended Hamilton principle is developed to derive coupled dynamic equations, with the nonlinear aerodynamic moment being formulated as an autonomous multiple-time-delay term to capture unsteady aerodynamic excitation. A wavelet-transform analysis of experimental data further identifies the system’s nonlinear restoring stiffness, providing a detailed characterization of its aeroelastic dynamics. The theoretical predictions agree well with experimental results. The compact and low-speed-capable harvester proposed herein represents a novel paradigm for efficient electromagnetic energy harvesting in confined or turbulent-flow environments.

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