Passive control is a classic method for enhancing the energy harvesting from flow-induced vibrations. This study introduces the Energy Concentration Pipe (ECP), a hollow pipe featuring a passive windward suction inlet and jet outlets, mounted on a circular cylinder to improve the performance of flow-induced vibration energy harvester. The effects of ECP configurations—single outlet, symmetrical dual outlet, and asymmetrical dual outlet—are investigated both experimentally and numerically. Experimental results demonstrate that the ECP significantly broadens the lock-in region and generates higher output voltage compared to conventional cylinders. Specifically, the lock-in region of the symmetrical dual outlet configuration increases by 108.33%, meanwhile the maximum output voltage improves by 12.69% over the baseline case. Numerical simulations further elucidate the mechanisms of the ECP, identifying the energy concentration phenomenon. An additional portion of incoming airflow, along with its energy, is channeled through the ECP and jetted into the wake vortex behind the cylinder, altering the wake vortex shedding process. The wake structure is characterized by large primary vortex pairs and smaller secondary vortices. The energy concentration also results in larger and stronger wake vortices, enhancing unsteadiness and broadening the lock-in region. Moreover, a transverse oscillation of vortices induces additional excitation on the cylinder due to pressure oscillation, leading to larger vibration amplitude and higher output voltage.

中文翻译：

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基于被动射流控制的能量集中管增强流激振动能量收集


被动控制是增强流动引起的振动能量收集的经典方法。本研究介绍了能量集中管（ECP），这是一种具有被动迎风吸入口和喷射出口的中空管，安装在圆柱体上，以提高流激振动能量收集器的性能。通过实验和数值研究了 ECP 配置（单出口、对称双出口和不对称双出口）的影响。实验结果表明，与传统气缸相比，ECP 显着拓宽了锁定区域并产生更高的输出电压。具体来说，对称双出口配置的锁定区域增加了108.33%，同时最大输出电压比基准情况提高了12.69%。数值模拟进一步阐明了 ECP 的机制，识别了能量集中现象。另一部分进入气流及其能量通过 ECP 引导并喷射到气缸后面的尾流涡流中，从而改变尾流涡流脱落过程。尾流结构的特点是具有较大的主涡对和较小的副涡。能量集中还会导致更大更强的尾流涡流，从而增强不稳定性并扩大锁定区域。此外，涡旋的横向振荡会因压力振荡而对气缸产生额外的激励，从而导致更大的振动幅度和更高的输出电压。