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Vertical tail buffeting alleviation using piezoelectric actuators-some results of the actively controlled response of buffet-affected tails (acrobat) program
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Moses, Robert W. |
| Copyright Year | 1997 |
| Description | Buffet is an aeroelastic phenomenon associated with high performance aircraft especially those with twin vertical tails. In particular, for the F/A-18 aircraft at high angles of attack, vortices emanating from wing/fuselage leading edge extensions burst, immersing the vertical tails in their wake. The resulting buffet loads on the vertical tails are a concern from fatigue and inspection points of view. Recently, a 1/6-scale F-18 wind-tunnel model was tested in the Transonic Dynamics Tunnel at the NASA Langley Research Center as part of the Actively Controlled Response Of Buffet Affected Tails (ACROBAT) Program to assess the use of active controls in reducing vertical tail buffeting. The starboard vertical tail was equipped with an active rudder and the port vertical tail was equipped with piezoelectric actuators. The tunnel conditions were atmospheric air at Mach 0.10. By using single-input-single-output control laws at gains well below the physical limits of the actuators, the power spectral density of the root strains at the frequency of the first bending mode of the vertical tail was reduced by as much as 60 percent up to angles of attack of 37 degrees. Root mean square (RMS) values of root strain were reduced by as much as 19 percent. The results herein illustrate that buffet alleviation of vertical tails can be accomplished using simple active control of the rudder or piezoelectric actuators. In fact, as demonstrated herein, a fixed gain single input single output control law that commands piezoelectric actuators may be active throughout the high angle-of-attack maneuver without requiring any changes during the maneuver. Future tests are mentioned for accentuating the international interest in this area of research. |
| File Size | 1401678 |
| Page Count | 22 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19970022378 |
| Archival Resource Key | ark:/13960/t2k69dn4h |
| Language | English |
| Publisher Date | 1997-04-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Design, Testing And Performance Root-mean-square Errors Tail Assemblies Mean Square Values Transonic Wind Tunnels Supersonic Aircraft Stabilizers Fluid Dynamics Vortices Piezoelectricity Wind Tunnel Models Control Theory Angle of Attack Aeroelasticity Active Control Buffeting Leading Edges Mach Number Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
