A review of aerodynamic design for hover-capable flapping-wing micro air vehicles

Hover-capable Flapping-Wing Micro Air Vehicles (FWMAVs), which mimic insects or hummingbirds, show extraordinary flight performance, such as hovering capability, high aerodynamic efficiency at low Reynolds numbers, and high biomimetic stealth, etc. Hover-capable FWMAVs can be used in disasters rescue, emergency response, and environmental monitoring, etc, presenting diverse applications. However, the aerodynamic forces and efficiency of flapping wings still lag significantly behind their biological counterparts, which adversely impacts the endurance and payload capacity of hover-capable FWMAVs, thus limiting their practical applications. This paper presents a comprehensive review of hover-capable FWMAVs, focusing on their current progress, theoretical and experimental methods for aerodynamic analysis, the high-lift mechanisms of insects and their applications in hover-capable FWMAVs, as well as the aerodynamic design methods and performance parameters of flapping wings. The key design parameters for achieving high lift, high aerodynamic efficiency, and low noise are identified, along with a clear outline of how these parameters influence performance. Finally, future directions for the aerodynamic design of hover-capable FWMAVs are discussed, providing valuable insights for subsequent researchers in the field.