Lanterna Rally

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Published: 1956

Total Pages: 0

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Results of an exploratory free-flight investigation at zero lift of several rocket-powered drag-research models equipped with 60 deg sweptback delta wings are presented for a Mach number range from about 0.70 to 1.60. The airfoil sections tested included the NACA 65-006 and a series of double-wedge sections with various thicknesses and positions of maximum thickness. The results of the investigation showed that, of the double-wedge sections with 6 percent thickness, the two sections with positions of maximum thickness at 20 and 50 percent of the chord had drag coefficients approximately equal through the transonic and supersonic Mach number range and had similarly occurring drag rises. The section with position of maximum thickness at 80 percent chord had a drag rise occurring at a Mach number M of approximately 0.15 lower than the drag rise of the other two sections. At M = 1.0, this section had drag coefficients more than twice as large as those of the other two sections; however, this difference decreased with increasing supersonic Mach numbers. The wing drag calculated by the linearized theory was in qualitative agreement with the test results in indicating the effects of varying the position of maximum thickness. The double-wedge section of 5 percent thickness with position of maximum thickness at 50 percent chord had fairly constant drag coefficients throughout the supersonic region, which ranged from about 50 to 80 percent of the drag coefficients for the similar section with twice the thickness ratio. The theoretical wing drag for this section was in very good agreement with the experimental value. The NACA 65-006 airfoil section had lower drag coefficients throughout the test region than any of the double-wedge sections of the same thickness ratio, although at the highest Mach numbers covered by these tests, the differences became very small.