Abstract：In this paper, a cantilever beam piezoelectric energy harvester suitable for low velocity water flow is designed. The five tips of the piezoelectric energy harvesters with the same mass and different section shape are experimentally studied in the open water channel. By changing the flow velocity in the water channel, the variations of power and frequency with the flow velocity for each energy harvester were obtained and compared. The results show that there is a starting flow velocity for every tip within the range of the experimental flow velocity, that the RMS power harvested by the piezoelectric energy harvester is about zero when the flow velocity is lower than the starting flow velocity; the power changes with the increase of the flow velocity, when the velocity is exceeding the starting flow velocity; the starting velocity of tip with similar section is relatively closer, the quadrangular prism is the lowest, cylinder is the next, triangular prism is the highest, that the energy harvest performance of energy harvesters with different tip is different, and the performance of triangular prism(70°) is the best, when the flow velocity is 0.54 m/s, the maximum power of 2.02 mW, which is 1.06, 2.58, 1.36 times as much as cylinder, quadrangular prism (50) and triangular prism (60°) respectively. The study can provide reference for the design of similar piezoelectric energy harvester.
2019, Vol. 40 
