National Aeronautics and Space Administration (NASA)
Published: 2018-07-18
Total Pages: 158
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A wind tunnel investigation was conducted in the Langley 12-Foot Low-Speed Wind Tunnel to study the low-speed stability and control characteristics of a series of four flying wings over an extended range of angle of attack (-8 deg to 48 deg). Because of the current emphasis on reducing the radar cross section of new military aircraft, the planform of each wing was composed of lines swept at a relatively high angle of 60 deg, and all the trailing-edge lines were aligned with one of the two leading edges. Three arrow planforms with different aspect ratios and one diamond planform were tested. The models incorporated leading-edge flaps for improved pitching-moment characteristics and lateral stability and had three sets of trailing-edge flaps that were deflected differentially for roll control, symmetrically for pitch control, and in a split fashion for yaw control. Top bodies of three widths and twin vertical tails of various sizes and locations were also tested on each model. A large aerodynamic database was compiled that could be used to evaluate some of the trade-offs involved in the design of a configuration with a reduced radar cross section and good flight dynamic characteristics. Moul, Thomas M. and Fears, Scott P. and Ross, Holly M. and Foster, John V. Langley Research Center AIRCRAFT DESIGN; DIRECTIONAL STABILITY; FLIGHT CHARACTERISTICS; LATERAL STABILITY; LEADING EDGE FLAPS; LOW SPEED STABILITY; RADAR CROSS SECTIONS; SWEPTBACK WINGS; TAIL ASSEMBLIES; TAILLESS AIRCRAFT; TRAILING EDGE FLAPS; WIND TUNNEL TESTS; ANGLE OF ATTACK; ASPECT RATIO; LEADING EDGES; PITCHING MOMENTS; ROLLING MOMENTS; TRADEOFFS; TRAILING EDGES; YAW...