MODELS
The 0.058-scale test model of a winged hypersonic research aircraft is shown (fig. 1) installed in a low-speed tunnel with a 12-foot (3.66 meter) octagonal test section at the Langley Research Center. The model was of modular design, as shown in figure 2, which allowed the build-up of four variations of the basic model (fig. 3) from two nose shapes, two fuselage base shapes, a forward delta, a positively cambered wing leading edge, a negatively cambered wing leading edge and wing tip fins. The model design rationale was primarily based on the stability and control requirements at the design hypersonic cruise Mach number range of 8 to 10. The two nose profiles are the result of different packaging arrangements. The scalloped base shape was designed to accommodate four rocket motors, one on top and three along the bottom of the fuselage base; however, on a small 0.021-scale hypersonic wind tunnel model the scale base proved to be too small to allow installation of a sting-mounted strain gage force balance. The base was, therefore, modified to the large semi-circular shape to accept the force balance, and was tested on the present large 0.058-scale model. The combination of the two nose and two base shapes made possible the four basic fuselage shapes of the present tests (see symbols list for designation). The forward delta was included in the design to help decrease the rearward shift of the aerodynamic center with Mach number. The negatively cambered wing was theoretically shown to markedly increase the Cmo at hypersonic speeds. Wing tip fins were designed with toe-in and located outboard of the fuselage wake to assure directional stability at hypersonic speeds and were interchanged with center vertical tails for the present tests. A streamlined subsonic center vertical tail and a hypersonic wedge-shaped center vertical tail were tested (fig. 3(b)) to assess the difference in directional stability and the effects on trim as compared with the tip fins. Elevons could be deflected from +5° to -30°. A model scramjet engine was also used to complete the model build-up (fig. 3(c)). The models were constructed of fiberglass and wood with all parts screw-attached and dowel-located on the basic wing-fuselage section. The balance was attached to a steel plate inside the wing-fuselage section. The geometric details of the models are shown in figure 3 and tabulated in table I.
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