Design, Analysis and Hover Performance of a Rotary Wing Micro Air Vehicle

An initial design concept for a micro‐coaxial rotorcraft using custom manufacturing techniques and commercial off‐the‐shelf components is discussed. Issues associated with the feasibility of achieving hover and fully functional flight control at small scale for a coaxial rotor configuration are addressed. Results from this initial feasibility study suggest that it is possible to develop a small scale coaxial rotorcraft weighing approximately 100 gm, and that moment control is sufficient for roll, yaw and lateral trim. A prototype vehicle was built and its rotors were tested in a custom hover stand used to measure thrust and power. The best measured rotor Figure of Merit, 0.42, was obtained for a single rotor configuration. A blade element momentum theory (BEMT) model of the rotor was implemented, and airfoil characteristics were estimated from the rotor tests. The model showed that profile drag accounts for 45% of the losses as opposed to 30% in full‐scale helicopters. The radio controlled vehicle was flown untethered with its own onboard power source and exhibited good flight stability and control dynamics.