Aerodynamic Analysis of Rotor Spacing and Attitude Transition in Tilt-Powered Coaxial Rotor UAV.

Complex aerodynamic characteristics and optimal control during the attitude transition of tilt-powered coaxial twin-rotor unmanned aerial vehicles (UAVs) represent key challenges in flight control design. This study investigates aerodynamic mechanisms and control parameter optimization during the transition of UAVs from vertical to forward flight. By establishing a dynamic model and combining theoretical and numerical analyses, the optimal rotor spacing is determined to be h = 0.

Porous graphene nanocages with wrinkled surfaces enhancing electrocatalytic activity of lithium/sulfuryl chloride batteries.

The lithium/sulfuryl chloride battery has been used as a primary power source because of its high energy/power density and level of safety. However, disadvantages regarding the sluggish kinetics of the electrode materials have limited its further energy related applications. Herein, we report an efficient approach to prepare nitrogen-doped graphene nanocages with high surface roughness to overcome this issue.