An experimental investigation on aerodynamic performance of a coaxial rotor system with different rotor spacing and wind speed

The present work analyses the aerodynamic complexities involved in the optimization of a coaxial rotor system in an attempt to maximize its performance in hover flight. Performance measurements (thrust and power consumption) of the system and the influence of design parameters (rotor spacing and wind speed) on performance are obtained with the aerodynamic momentum theory and the hover test stand. Combined with the error analysis, the systematic testing of isolated rotor (top rotor and bottom rotor) is performed to give a performance baseline for the coaxial rotor system. Rotor spacing experiments indicated that the aerodynamic interference with different spacing generated different thrust and powers in hover flight, and the performance was indeed improved with a proper spacing as compared to the large rotor. Furthermore, the effect of the wind speed on the rotor performance is also studied as the external disturbance to help study the aerodynamic performance of the coaxial rotor system. Test results showed that the horizontal wind played a dominant role on the rotor aerodynamics while the effect of the vertical wind is relatively stable.

► There is no similar experimental study on this novel rotor configuration.
► Seven rotor spacing test combined with the wind tunnel test are studied and validated.
► Low Reynolds number and air viscous are involved in these experiments.
► This research will implement in a twelve rotor MAV in the future work.