Development and Analysis of a Coaxial Rotor Test Bench in Axial Flow Conditions

Small-scale coaxial-rotor assemblies are commonly utilized in Unmanned Aerial Vehicles to provide a compact design solution for achieving increased thrust potential and flight stability. The presence of two rotors operating in close proximity to each other results in aerodynamic interactions that have a profound effect on the individual rotor performance. A dedicated coaxial rotor test bench was developed for the purpose of testing various setups in a multi-rotor arm configuration. This study investigates the influence of different propeller blade geometries, number of rotor blades, and rotor separation distances on the aerodynamic, electric, and system performance of coaxial rotor configurations in static thrust conditions. Furthermore, the thrust and power measurements for one configuration is presented in axial and reverse flow conditions.