This research investigated the effect of span length variation and capless prismatic structure on the performance of the micropower generator from flow-induced vibration. The vibration response type covers galloping and vortex-induced vibration regimes. The mini harvester energy induced by the harmonic oscillation of prismatic structure was implemented based on the magnetostrictive principle to gain electricity using a galfenol alloy (Fe-Ga). The power generation variations are influenced by the amplitude, frequency, structure displacement, span length, and shape of the bluff body. The optimum power generation is 2.87 mW, and the maximum power generation is 10.63 mW at the resonance velocity Vr of 6.45. Reducing the frequency characteristics of circular cylinders by applying a cap end tip affect power generation characteristics and galloping behaviour for the prism with a span length of 200 mm but not for other span lengths. The effect of span length variation on free vibration and power generation performance for all prism models is similar in that both features are decreased by increasing span length. However, it enhances onset valued power generation. Power generation is considered for the independent electricity supply for specific sensor or wireless devices of an IoT system.
