Design Of A Six-Axis Aerodynamic Balance For Phase-Lag Measurements On Tilt-Mounted Helicopter Rotors

Abstract

This paper describes the design, development, and validation of an aerodynamic balance that uses a Stewart platform-based six-axis force/torque sensor. The main objective is to measure the forces and moments generated by the tilt-mounted helicopter rotor equipping the TIDAV T-H3 vertical take-off and landing (VTOL) drone. Additionally, it is crucial in measuring the previously observed 35° phase lag. Due to the 31" rotor diameter, stiff carbon fiber blades and absence of a flapping hinge, this value differs from the standard phase lags observed in conventional helicopter rotors, which typically range from 75° to 90°, depending on the hinge technology. The first part of the paper details the design process, the calibration of the six sensors, and the accuracy of the balance using a standard multicopter rotor. The balance is then used to measure the performance and the phase lag of the T-H3 tiltrotor.