Wind energy harvesting using electromagnetic dual and multi cantilever flutter array

Abstract

This study investigates wind energy harvesting from electromagnetic dual cantilever flutter (DCF) and multi cantilever flutter (MCF) arrays. Initially, the bare DCF was tested under several wind speeds at four different gap distances to analyse and verify its behaviour. Results suggest that the characteristics of the DCF is ideal for electromagnetic energy harvesting. Two identical sets of wounded coils and magnets were then fixed onto the DCF to generate an induced voltage output from the anti-phase motion. Experimental findings demonstrated a significant power density of 11 × 10−3 mW/cm3 at a wind speed of 18.0 ms−1 when using shorter and thicker beams, which is comparable to previous flutter-based energy harvesters. An additional magnet-holding beam was then added beside the DCF beams to form a multi cantilever flutter (MCF) array of three identical beams. Visual observation confirms that alternate beams in the MCF array also flutter in an anti-phase motion. The power output per beam and power density recorded for the MCF array was 38.0% higher than the DCF harvester due to the increase in functional coil output and magnetic flux density. Finally, further analysis suggest that an odd number of beams is more favourable for electromagnetic MCF array harvesters.