R. Kube

In order to investigate the effect of Higher Harmonic Control (HHC) on a hingeless rotor, a wind tunnel demonstration was perlormed with the DLR rotor test rig in the German Dutch Wind Tunnel (DNW). The test yielded an Impressive result and showed, that a considerable vibration reduction is possible by applying a higher harmonic blade pitch angle to the rotor. Furthermore a simultaneous reduction of all dynamic rotor forces and moments could be achieved with a pure 3/rev or 4/rev blade pitch angle respectively, an unexpected result which can only be explained by aer0elastic phenomena. In order to verify this assumption and to find the reason for the high 3/rev and 4/rev efficiency the wind tunnel data were compared with simulation results attained with different rotor and downwash models. They show the Influence of various aerodynamic and aeroelastlc phenomena on the rotor behaviour and give an explanation for the rotor characteristic ascertained In the wind tunnel. A so called Single Output Controller (SOC) which, although working with a 3/rev blade pitch angle only, succeeds In suppressing the vibrations in all degrees of freedom and, in addition, Is able to keep them small even In case of fast maneuvers finally covers the appflcationar aspect of the new wind tunnel findings.

International Forum on Aeroelasticity and Structural Dynamics 1991, Aachen

Conference Paper

englisch

21,0 x 29,7 cm, 9 Seiten

DGLR-Bericht, 1991, 1991-06, International Forum on Aeroelasticity and Structural Dynamics 1991 Proceedings; S.496-504; 1991; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroelasticity

Bestellbar

1991