带状附加物放置角度对流致振动与振子俘能特性影响研究

Experimental study on the influence of the placement angles of strip attachments on the flow induced vibration of a cantilever vibrator and the energy harvesting characteristics

流致振动普遍存在于工程领域与自然界,由于复杂性和多学科交叉的特点,流致振动一直是学界研究热点之一,利用被动湍流控制(passive turbulence control,PTC)来增强流致振动的俘能技术更是受到了广泛关注。该文章在光滑圆柱上放置不同角度的对称带状方形附加物,试验得到了振子的振幅、振动频率、输出功率、能量转换效率和振子升力系数,进一步揭示了被动湍流控制增强流致振动的机理。研究结果表明:PTC圆柱振子的最大振幅为2.0 D,是光滑圆柱振子最大振幅的5倍;最大输出功率达0.44 W,是光滑圆柱振子最大输出功率的14倍。这说明合理的配置附加物的放置角度,可以使振子的振动由涡激振动(vortex-induce vibration,VIV)发展为驰振,同时获得较高的输出功率和能量转换效率,为利用流致振动进行能量转换和收集提供了必要的理论指导和技术支撑。

Flow induced vibration generally exists in the field of engineering and nature.Due to the complexity and interdisciplinary,the flow induced vibration has always been one of the research hotspots in the academic community.The energy harvesting technology using passive turbulence control(PTC)to enhance flow induced vibration has attracted extensive attention.The characteristics of flow induced vibration of a cantilever vibrator by placing symmetrical square strip attachments with different angles on a smooth cylinder were focused on.The response amplitude and frequency,output power and energy conversion efficiency,and the lift coefficient were obtained.The mechanism of passive turbulence control to enhance flow induced vibration was further revealed.The results show that the maximum amplitude of a PTC cylindrical vibrator is 2.0 D,which is 5 times that of a smooth cylindrical vibrator;the maximum output power is 0.44 W,which is 14 times of the maximum output power of the smooth cylindrical vibrator.The reasonable placement angle of the attachment can make the vibration of the vibrator develop from vortex induced vibration to galloping,and obtain high output power and energy conversion efficiency.The results provide necessary theoretical guidance and technical support for energy conversion and collection by flow induced vibration.