Aerodynamics and dynamic stability of micro-air-vehicle with four flapping wings in hovering flight

Abstract

Recently, a novel concept of flapping Micro-Air-Vehicles (FMAVs) with four wings has been proposed, which potentially utilizes the clap-and-fling effect for lift enhancement and agile maneuvers through an adjustment of wing kinematics. However, the application of the clap-and-fling effect in the four-winged FMAVs is underexplored and the dynamic stability is still unclear. In this paper, aerodynamics and flight dynamic stability of the four-winged FMAVs are studied experimentally and numerically. Results show that the clap-and-fling effect is observed when the flapping frequency is above 18 Hz. Due to the clap-and-fling effect, the lift generation and aerodynamic efficiency are both improved, which is mainly attributed to the fling phase. Further studies show that the clap-and-fling effect becomes weaker as the wing root spacing increases and is almost absent at a wing root spacing of 1.73 chord length. In addition, a wing with an aspect ratio of 3 can increase both lift generation and efficiency due to the clap-and-fling effect. Finally, according to the dynamic stability analysis of the four-winged FMAV, the divergence speed of the lateral oscillation mode is about 4 times faster than that of the longitudinal oscillation mode. Our results can provide guidance on the design and control of four-winged FMAVs.

Biomimetic Drones Inspired by Dragonflies Will Require a Systems Based Approach and Insights from Biology

“…Mathematical modelling helps gain insight into the complexities associated with flapping flight. Several flight dynamics models for insects have been developed in the literature [60,[62][63][64][65][66][67][68]; however, most of the models are data-driven for specific insects and, as such, are specific and restrictive in application. Flapping flight dynamics models in the literature, based on laws of classical physics, have neglected effects due to morphological changes.…”