High Load Investigations of The Smart Twisting Active Rotor (STAR) -Comparison of Pre-test Simulations with Wind Tunnel Results

Kurzfassung

The Smart Twisting Active Rotor (STAR) wind tunnel campaign has recently been completed. From the extensive test matrix, this paper focuses on the high-load operating condition, in which the rotor was investigated in both actuated and unactuated configurations under dynamic stall conditions. The experimental results are compared with numerical predictions generated both before and after the wind tunnel campaign. In addition to identifying beneficial active-twist settings for reducing rotor power consumption and vibration levels, the study assesses the predictive capabilities of the employed simulation methods, ranging from comprehensive rotorcraft analyses to coupled CFD/CSD simulations. For the unactuated rotor, reasonable agreement with the measured power consumption is achieved, whereas for the actuated rotor only some of the observed trends are captured. Accurate prediction of vibratory loads remains challenging. Nevertheless, the experiments demonstrate that active twist can reduce rotor vibrations by up to 42% compared with the unactuated baseline configuration.