The Smart Twisting Active Rotor (STAR) Test in the LLF of the DNW - A Joint German, French, US, Korean, Japan and Dutch Project

Kurzfassung

After 20 years of development of active twisting model rotor blades at DLR a highly instrumented set of model rotor blades was manufactured for wind tunnel testing. An international cooperation including the German DLR, French ONERA, NASA and DEVCOM AvMC, KARI and Konkuk University, Japan JAXA and German-Dutch Wind Tunnels (DNW) was established. Year-long prediction activities were performed to numerically explore the potential benefits of actively twisting rotor blades, aiming to reduce the noise radiation and rotor vibration, improve the rotor performance and efficiency, and to explore rotor stall characteristics at cruise and high advance ratios. All partners commonly funded and executed a 12-days rotor test in October 2025 in the low-noise open-jet configuration of the Large Low-Speed Facility of the DNW. Test data from hover, level flight, low-speed climb-to-descent, rotor stall at cruise advance ratio and slowed rotor high advance ratio, without and with active twist, are now available for code validation.