Design, Fabrication and Hovering Performance Study of Nano Coaxial Rotor

Abstract

Department of Astronautics, Northwestern Polytechnical University,Xi’an, 710072, China. xumin@nwpu.edu.cnAccepted 6 September 2011A nano coaxial rotor was designed, fabricated and studied experimentally at an ultra-low Reynolds number ranging from 5000 to 20,000. The Minimum Induced Loss theorywas employed to optimize the geometry of nano coaxial rotor with the introduction ofweights to take into account the interference of upper rotor and lower rotor. The chordand twist distributions of both rotors were achieved as a result. Nano coaxial rotor wasthen fabricated with a lightweight material of carbon laminate. Two rotor slices wereobtained with mass less than 0.3 g and the thickness less than 0.23 mm. Successively, asensitive test bench was designed to measure the hovering performance of nano coaxialrotor. Single upper rotor and lower rotor were tested with the test bench as well asthe isolated upper rotor and lower rotor of nano coaxial rotor. It is found that thedesigned nano coaxial rotor can generate a thrust of 0.105 N with torque cancelled. Andthe comparison between single rotor and isolated rotor of nano rotor showed that themutual interaction between rotors improves upper rotor performance but impairs lowerrotor performance.Keywords: Nano Air Vehicle; Nano coaxial rotor; Design and fabrication; Hovering per-formance.