Sizing process, aerodynamic analysis, and experimental assessment of a biplane flapping wing nano air vehicle

Abstract

The design, manufacturing, experimentation, performance analysis, and flight test for a biplane flapping wing nano air vehicle, capable of both forward and hovering flight are presented. To design this nano air vehicle, a comprehensive sizing method based on theoretical and statistical analyses is proposed and experimentally verified. Then, aerodynamic analyses based on quasi-steady and strip theory methods are conducted to select the optimum values for the kinematics. To evaluate the proposed conceptual design obtained from the sizing methodology and aerodynamic analyses, an experimental setup deploying strain gauges mounted on a thin aluminum plate is implemented. This setup is also deployed to identify the wing configuration resulting in the highest thrust generation and lowest power consumption. The experimental results are found in a good agreement with the aerodynamic simulations. To ensure the stability of the air vehicle and a smooth transition between the different flying modes, magnetic coils are mounted on the tail to actuate the elevator and rudder. A flight test was successfully performed indoor to demonstrate the flying capabilities of the air vehicle and the camera showed a clear visual inspection of the area. It showed stable behavior especially during the transition from forward flight to hovering and superior flight endurance in comparison to similar air vehicles reported in the literature. The proposed and applied design methodologies along with the manufacturing process are expected to provide useful guidelines to design and manufacture different types of flapping wings to support various applications.

Insights into Sensitivity of Wing Shape and Kinematic Parameters Relative to Aerodynamic Performance of Flapping Wing Nano Air Vehicles

“…Figure 1. Views of (a) power consumption and (b) thrust to power ratio versus flapping frequency [44].…”

“…Hassanalian et al [7] has presented an empirical equation for flapping frequency estimation. In addition, Ghommem et al [44] have recently published a work on the design and fabrication of a flapping wing NAV and have estimated a flapping frequency of 20-47 Hz. Their experimental verification of the flapping wing NAV was also carried out for 20-47 Hz.…”

“…ϕ is the angular velocity of the wing root joint and τ is the flapping time period. In FlapSim, for aerodynamic modeling, a quasi-steady model (blade-element theory) is used which neglects the unsteady aerodynamic effects [30,44,45]. In this model, the aerodynamic force coefficients are the…”

“…Although some unsteady models may yield better aerodynamic performance predictions, such as Phan et al [42], Parslew et al [43] have shown that the model being used provides sufficient predictions at lower computational costs. In addition, Ghommem et al [44] have validated FlapSim predications with experimental data for a flapping wing NAV (FWNAV), as can be seen in Figure 1. The FlapSim predictions agree with the experimental results obtained here but underpredict the thrust/power at higher flapping frequencies.…”

Towards Improved Hybrid Actuation Mechanisms for Flapping Wing Micro Air Vehicles: Analytical and Experimental Investigations

“…Delfly MAV is powered by a DC electric motor coupled to a gearbox and linkage mechanism using conventional pin joints [12]. At NAV scale, AeroEnvironment company has recently designed and fabricated a flapping wing NAV like a hummingbird, which is capable of flying in hover mode [16]. This Nano-Hummingbird uses an actuation mechanism composed of rollers and strings, while still using a geared down motor to provide power at the right frequency [17][18][19].…”