Time-averaged flowfield measurements of a coaxial rotor to understand the rotor-on-rotor interactions in hover

The presence of two rotors stacked on a single axis in a counter-rotating coaxial rotor configuration experiences significant aerodynamic interactions. These interactions dominate the operating environment of the individual rotors and their performance. The present work investigates this rotor-on-rotor interaction phenomenon using simultaneous load and flowfield measurement. The spanwise inflow variation is extracted by averaging the axial velocities at a location above and below the rotor plane obtained from time-averaged flowfield measurements. The individual rotor inflow is then compared with the thrust equivalent single rotor to understand the effect of one rotor on another. The experiments are conducted at two axial spacing and for two different thrust settings to comprehend its impact on rotor-on-rotor interactions. This research will explore the effect of flow physics on individual rotors' performance in a coaxial configuration.