Abstract The advantageous performance on energy conversion of triangular prisms in Flow Induced Motion Energy Conversion (FIMEC) system has been verified by previous researches. In this paper, the magnetic flux density (B) was introduced into the mathematical model to analyze damping (ctotal), active power (Pharn) and energy conversion efficiency (ηharn) in FIMEC system. A physical model was established to adjusted the magnetic flux density (B) by varying the excitation voltages (VB) of Power Take-Off System (PTO). Free decay tests proved that physical model matched well with the mathematical model. Based on the physical model, the Flow Induced Motion (FIM) characteristic and energy conversion were analyzed and discussed, furthermore a control strategy to harness energy in galloping branch for Hard Galloping (HG) was proposed and verified. As B is high HG occurs, otherwise soft galloping (SG) occurs. By using the control strategy, the galloping can be self-excited by adjusting B, which is beneficial to the energy conversion of FIM. In the tests, the peaks of active power and efficiency are Pharn ≈ 2W and ηharn ≈ 3.1% in Vortex Induced Vibration (VIV) upper branch, Pharn ≈ 21.5 W and ηharn ≈ 3.5% in galloping branch.

中文翻译：

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改变发电机磁通密度对三棱柱流致运动的流体动能转换

摘要 三棱柱在流动诱导运动能量转换（FIMEC）系统中能量转换的优越性能已被前人的研究证实。在本文中，将磁通密度（B）引入数学模型来分析FIMEC系统中的阻尼（ctotal）、有功功率（Pharn）和能量转换效率（ηharn）。建立了一个物理模型，通过改变取力器系统 (PTO) 的励磁电压 (VB) 来调整磁通密度 (B)。自由衰变试验证明物理模型与数学模型匹配良好。基于物理模型，分析和讨论了流动诱导运动（FIM）特性和能量转换，并提出并验证了一种控制策略，用于在奔腾分支中利用能量进行硬奔腾（HG）。由于 B 是高 HG，否则会发生软疾驰 (SG)。采用该控制策略，可以通过调节B实现飞驰自激，有利于FIM的能量转换。在测试中，有功功率和效率的峰值在涡激振动 (VIV) 上分支中分别为 Pharn ≈ 2W 和 ηharn ≈ 3.1%，在飞驰分支中 Pharn ≈ 21.5 W 和 ηharn ≈ 3.5%。