横流式水轮机下游悬臂梁对微能量采集性能的影响（英文）

Effect of Cantilever Beams in The Downstream of Cross-flow Hydroturbine for Micro-energy Harvesting

横流式水轮机在叶轮处将势能转化为动能,与此同时会在转轮尾流中引发一种称为涡激振动(VIV)的流动现象。横流式水轮机的VIV是一种由绕虚拟涡轴线的流动所诱发的非定常流动现象。这种振动可以作为一种压电能量的采集来源。本文采用商用CFD软件ANSYS CFX 17.1对横流式水轮机进行了数值分析,考察其微能量采集的性能(MEH)。在研究过程中,于横流式水轮机下游布置了悬臂梁,并考察了悬臂梁间距对微能量采集性能的影响。本文给出了不同流动和几何条件下的速度矢量和涡流强度分布图。

Cross-flow hydroturbine harvests potential energy as kinetic energy at the impeller,and a flow phenomenon which called vortex induced vibration(VIV)is occurred in the wake of runner.The VIV of cross-flow hydroturbine is an unsteady flow phenomenon,which is induced by a fluid flowing around an axis of virtual vortex.This vibration could be used as a source of piezoelectric energy harvesting.In this study,numerical analysis of cross-flow hydroturbine was carried out for confirming the performance of micro-energy harvesting(MEH)using the commercial CFD code,ANSYS CFX 17.1.Cantilever beams were located at the downstream of cross-flow hydroturbine and the performance of micro-energy harvesting was evaluated according to the distance of cantilever beams.The velocity vector field and swirl strength are graphically depicted with various flow and geometrical conditions.