Browsing by Author "Nguyen, Quoc Viet"

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    Bioinspired low-noise wing design for a two-winged flapping-wing micro air vehicle
    (AIAA, 2018-10-15) Lu, Zhenbo; Debiasi, Marco; Nguyen, Quoc Viet; Chan, Woei-Leong
    This work investigates the acoustic and thrust performances of different wing designs for a two-winged flapping-wing micro air vehicle (FW-MAV). The reference wings, made of a Mylar film membrane supported by carbon-fiber rods, produce a perceived overall noise of about 68.8 dBA when operating at the flapping frequency of 10 Hz typically required for flying such a flapping wing vehicle. This noise is much higher than the value of the environmental background. Wings of various materials and structural configurations are designed and tested in order to reduce the flapping-wing noise. Sound and force measurements are used to assess their acoustic and lift capabilities. It is found that a wing made with a highly elastic dielectric elastomer membrane can reduce the overall perceived noise of the flapping wing by 12 dBA while slightly increasing the thrust. The mechanisms leading to this noise reduction and their potential applications in quiet FW-MAVs are discussed.
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    Experimental investigation of wing flexibility on force generation of a hovering flapping wing micro air vehicle with double wing clap-and-fling effects
    (Sage, 2017-03) Nguyen, Quoc Viet; Chan, W. L.; Debiasi, Marco
    Experimental investigation of wing flexibility on vertical thrust generation and power consumption in hovering condition for a hovering Flapping-Wing Micro Air Vehicle, namely FlowerFly, weighing 14.5 g with a 3 g onboard battery and having four wings with double wing clap-and-fling effects, was conducted for several wing configurations with the same shape, area, and weight. A data acquisition system was set up to simultaneously record aerodynamic forces, electrical power consumption, and wing motions at various flapping frequencies. The forces and power consumption were measured with a loadcell and a custom-made shunt circuit, respectively, and the wing motion was captured by high-speed cameras. The results show a phase delay of the wing tip displacement observed for wings with high flexible leading edge at high frequency, resulting in less vertical thrust produced when compared with the wings with less leading edge flexibility at the same flapping frequency. Positive wing camber was observed during wing flapping motion by arranging the wing supporting ribs. Comparison of thrust-to-power ratios between the wing configurations was undertaken to figure out a wing configuration for high vertical thrust production but less power consumption.
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    Low-noise flapping wings with tensed membrane
    (AIAA, 2020-04-15) Debiasi, Marco; Lu, Zhenbo; Nguyen, Quoc Viet; Chan, Woei Leong
    Micro air vehicles with flapping wings have the potential to be both more efficient and maneuverable than similar-sized fixed- or rotary-wing aircraft. Reducing the perceived noise produced by flapping wings without compromising or possibly enhancing their aerodynamic performance would be crucial in surveillance and military applications. To this aim, flapping wings have been designed and fabricated for which the supporting stiffeners tense the Mylar membrane to which they are bonded. The sound produced by these wings at different flapping frequencies has been recorded in an anechoic chamber simultaneously to the upward thrust they create. Comparing their characteristics and performance with those of flapping wings of conventional design suggests that tensing the wing’s membrane can increase the thrust while decreasing the typical rustling noise of the flapping wings