Skip to main content

New Aspects of Higher Harmonic Control on a Four‐Bladed Hingeless Model Rotor

Buy Article:

$22.00 plus tax (Refund Policy)

To investigate the effect of Higher Harmonic Control (HHC) on a hingeless rotor, a wind‐tunnel demonstration was performed with open‐ as well as closed‐loop tests. Whereas the open‐loop tests aimed at a systematic examination of the rotor dynamics in the case of HHC inputs, the main aspect of the closed‐loop tests was the behavior of an implemented adaptive controller. A first data evaluation showed that the controller reduced the vibrations considerably at steady‐state as well as at time‐varying flight conditions. Surprisingly, however, all dynamic rotor forces and moments could be influenced simultaneously by single HHC input signal. Furthermore, a nearly constant phase shift of the rotar transfer function was ascertained within the whole flight envelope. These rotor characteristics are demonstrated by wind tunnel data and theoretical explanations are provided. Theoretical explanations are supported by simulation results obtained with different aeroelastic rotor and rotor downwash models, showing the influence of various aerodynamic and aeroelastic parameters on the measured rotor characteristics. Finally, a controller that works with a constant feedback phase shift of the rate transfer function is presented and compared with a fully adaptive one.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Affiliations: DLR Institute for Flight Mechanics, Braunschweig, Germany

Publication date: 1992-07-01

More about this publication?
  • The Journal of the American Helicopter Society is the world's only scientific journal dedicated to vertical flight technology. It is a peer-reviewed technical journal published quarterly by AHS International and presents innovative papers covering the state-of-the-art in all disciplines of rotorcraft design, research and development. (Please note that AHS members receive significant discounts on articles and subscriptions.)

    Journal subscribers who are AHS members log in here if you are not already logged in.

    Authors can find submission guidelines and related information on the AHS website.

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more