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美国政府科技报告
>INVESTIGATION OF THE NORMAL-FORCE,nAXIAL-FORCE, AND PITCHING-MOMENT CHARACTERISTICSnOF BLUNT LOW-FINENESS-RATIO BODIES OF REVOLUTIONnAT A MACH NUMBER OF 3.55
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INVESTIGATION OF THE NORMAL-FORCE,nAXIAL-FORCE, AND PITCHING-MOMENT CHARACTERISTICSnOF BLUNT LOW-FINENESS-RATIO BODIES OF REVOLUTIONnAT A MACH NUMBER OF 3.55
An investigation of the normal-force, axial-force, and pitching-moment characteristics of blunt, low-fineness-ratio bodies of revolu¬tion has been made at a Mach number of 3.55. The results indicate that, for cylinders having fineness ratios of 1.00 and 0.50, rounding the corners of the noses caused large decreases in the axial-force coeffi¬cients, moderate increases in the slopes of the normal-force curves, and very small changes in the slopes of the pitching-moment curves. Varying the half-angles of cylinder-cone frustums and spherical-faced cone frustums had large effects on the axial-force coefficients and static stability in pitch. For exponential shapes, increasing the exponent from 2 to 10 generally increased the axial-force coefficients, decreased the slopes of the normal-force curves, and decreased the sta¬bility in pitch. For a fineness ratio of 1.00 a parabolic body had the least drag, and for a fineness ratio of 0.50 an exponential shape having an exponent of 3 had the least drag. A 26.6° cone and the parabolic body having a fineness ratio of 1.00 had the highest values of normal-force curve slope. All the bodies were statically stable in pitch about a point one-third of the body length rearward from the face, and a spherical-faced cone frustum was the most stable body in pitch. Little variation of axial-force coefficient with angle of attack was obtained for any of the bodies.
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