Innovative blade shape for micro wind turbines

This study reports the design and fabrication of innovative blades for a centimeter-scale propeller and the experimental testing of a wind harvester. A samara wing structure is taken as a model to optimize the aerodynamics at low Reynolds number. The performances of the 44 mm diameter horizontal-axis micro wind turbine are tested in two dedicated wind tunnels, with wind speeds from 1.2 m$.\mathrm{s}^{-1}$ to 8 m$.\mathrm{s}^{-1}$. The output electrical powers range from $50 \mu \mathrm{W}$ to 80 mW, with a maximal overall efficiency of 17.5% for 4 m$.\mathrm{s}^{-1}$. It appears that this bio-inspired prototype have better performances than almost all the previous studies on small-scale wind harvesters in a large wind speeds range, and gives hope to get even higher.