Loading...
Please wait, while we are loading the content...
Similar Documents
An approximate closed-form solution for lead lag damping of rotor blades in hover
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Peters, D. A. |
| Copyright Year | 1975 |
| Description | Simple stability methods are used to derive an approximate, closed-form expression for the lead-lag damping of rotor blades in hover. Destabilizing terms are shown to be a result of two dynamic mechanisms. First, the destabilizing aerodynamic forces that can occur when blade lift is higher than a critical value are maximized when the blade motion is in a straight line equidistant from the blade chord and the average direction of the air flow velocity. This condition occurs when the Coriolis terms vanish and when the elastic coupling terms align the blade motion with this least stable direction. Second, the nonconservative stiffness terms that result from pitch-flap or pitch-lag coupling can add or subtract energy from the system depending upon whether the motion of the blade tip is clockwise or counterclockwise. |
| File Size | 731293 |
| Page Count | 27 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19750014204 |
| Archival Resource Key | ark:/13960/t41s1kf1v |
| Language | English |
| Publisher Date | 1975-04-01 |
| Access Restriction | Open |
| Subject Keyword | Aerodynamics Damping Hovering Stability Helicopter Control Stiffness Critical Loading Aerodynamic Forces Equations of Motion Coriolis Effect Rotary Wings Pitch Inclination Time Lag Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
