Experimental study on acoustic and aerodynamic improvement of the hemiptera-inspired propeller planform

The multi-rotors have a short working duration and produce excessive noise, which is insufficient for complicated jobs and has a negative impact on human and animal health. Nonetheless, their market is growing in popularity. As a result, low-noise products are more competitive, and aerodynamic and acoustic enhancements are essential. The goal of this research is to create a small bioinspired propeller with the same power input as a conventional propeller that achieves the same or better aerodynamic performance while reducing noise. Accordingly, an experiment looked at the effects of different operating circumstances and geometric factors on the aerodynamic and aeroacoustic performance of a small propeller with a distinctive planform shape inspired by Hemiptera. This propeller was run at eleven rotational speeds ranging from 3000 to 8000 RPM with no freestream velocity to simulate hover circumstances. When compared to the baseline propeller, the Hemiptera propeller produce greater thrust for the same power source, reduce harmonic and broadband noise, and offer a better noise level. This noise reduction might be attributed to a decrease in Hemiptera propeller force fluctuation. Furthermore, its rotational speed is lower and its figure of merit is higher than the baseline propeller at hover flying with 3N thrust. Moreover, at this force, the Hemiptera propeller shows a 2.8W power reduction and a 5 dB decrease in acoustic signature. When it comes to hover efficiency, the Hemiptera propeller outperforms the baseline propeller across the board, regardless of thrust.