NOSE BLUNTNESS, CONE ANGLE, AND MACH NUMBER EFFECTS ON THE STABILITY DERIVATIVES OF SLENDER CONES
AEROSPACE RESEARCH LABS WRIGHT-PATTERSON AFB OH
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A theoretical and experimental study to evaluate the influence of spherical nose bluntness, of cone angle, c. g. location and Mach number on the stability characteristics in pitch of blunt slender cones was conducted. A 10- degree half-angle cone with nose bluntness ratios from .025 to .30 was investigated. The observed effect of the nose bluntness on the stability derivatives was quite similar to earlier results with a 5.6 degree half-angle cone. Again, a severe breakdown of the damping derivatives was found for large bluntness ratios. An estimate of the pitch-induced angles of attack for large bluntness ratios was based on the physics of the blast wave type flow. It was found that these induced angles differ from those applicable for pointed cones or for small bluntness ratios where the flow has mainly conical character. The tangent cone method in connection with these different types of pitch-induced angles of attack qualitatively predicts the observed breakdown of the damping derivatives.
- Fluid Mechanics