Small scale flow energy harvesters are designed to operate at low elevations where surface effects cause significant flow velocity variations. To harness flow energy efficiently in such environments, the harvester must be very sensitive to flow fluctuations. In particular, the rise time of the harvester to the steady-state value must be short. This Letter proposes a method to reduce the rise time of galloping flow energy harvesters by passively manipulating the flow near the trailing edge. To this end, the rear face of the square prism typically used in galloping energy harvesting is augmented with Y-shaped fins of different lengths and fork angles. The addition of the fins is shown to significantly increase the rate at which the magnitude of the normal force coefficient grows with the angle of attack. This, in turn, can reduce the rise time of the harvester by as much as 75% when compared to the finless square prism. The addition of the fins has no detrimental influence on the steady-state performance of the harvester. On the contrary, the steady-state voltage of the harvester can also be improved for some fin geometries.

中文翻译：

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提高驰骋能量采集器对流量波动的敏感性

小型流动能量收集器设计用于在表面效应导致显着流速变化的低海拔地区运行。为了在这种环境中有效地利用流动能量，收割机必须对流动波动非常敏感。特别是，收割机达到稳态值的上升时间必须很短。这封信提出了一种通过被动操纵后缘附近的流动来减少奔腾流动能量收集器的上升时间的方法。为此，通常用于驰骋能量收集的方形棱镜的背面增加了不同长度和叉角的 Y 形鳍片。显示翅片的添加显着增加法向力系数的大小随迎角增长的速率。这反过来，与无鳍方形棱镜相比，可以将采集器的上升时间减少多达 75%。翅片的添加对收割机的稳态性能没有不利影响。相反，对于某些鳍片几何形状，收集器的稳态电压也可以提高。