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Accession Number N20120014506
Title Forced Oscillation Wind Tunnel Testing for FASER Flight Research Aircraft.
Publication Date Aug 2012
Media Count 12p
Personal Author C. Denham D. B. Owens G. Hoe
Abstract As unmanned air vehicles (UAVs) continue to expand their flight envelopes into areas of high angular rate and high angle of attack, modeling the complex unsteady aerodynamics for simulation in these regimes has become more difficult using traditional methods. The goal of this experiment was to improve the current six degree-of-freedom aerodynamic model of a small UAV by replacing the analytically derived damping derivatives with experimentally derived values. The UAV is named the Free-flying Aircraft for Sub-scale Experimental Research, FASER, and was tested in the NASA Langley Research Center 12- Foot Low-Speed Tunnel. The forced oscillation wind tunnel test technique was used to measure damping in the roll and yaw axes. By imparting a variety of sinusoidal motions, the effects of non-dimensional angular rate and reduced frequency were examined over a large range of angle of attack and side-slip combinations. Tests were performed at angles of attack from -5 to 40 degrees, sideslip angles of -30 to 30 degrees, oscillation amplitudes from 5 to 30 degrees, and reduced frequencies from 0.010 to 0.133. Additionally, the effect of aileron or elevator deflection on the damping coefficients was examined. Comparisons are made of two different data reduction methods used to obtain the damping derivatives. The results show that the damping derivatives are mainly a function of angle of attack and have dependence on the non-dimensional rate and reduced frequency only in the stall/post-stall regime
Keywords Aerodynamic forces
Angle of attack
Degrees of freedom
Flight envelopes
Flight tests
Free flight
Low speed wind tunnels
Pilotless aircraft
Research aircraft
Rolling moments
Static tests
Wind tunnel tests

Source Agency National Aeronautics and Space Administration
NTIS Subject Category 51C - Aircraft
51F - Test Facilities & Equipment
Corporate Author National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.
Document Type Conference proceedings
Title Note N/A
NTIS Issue Number 1308
Contract Number N/A

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