Effect of Unsymmetrical Nose-Bluntness on the Stability Derivatives of a 10 Degree Cone at Mach-14

In the analysis of the free flight motion of bodies of revolution, the tricyclic theory assumes that a small configurational asymmetry does not violate the rotational symmetry of the stability derivatives in pitch and yaw but does produce a non-zero trim angle. Tests at Mach 14 show that a small unsymmetric nose bluntness destroys the rotational symmetry of the stability derivatives of a slender cone at hypersonic Mach numbers and therefore severely violates the assumptions of the tricyclic theory. Restoring and damping derivatives in pitch and yaw are reported for a 10 deg cone with symmetric and unsymmetrically blunted noses. The effect of non-equal stability derivatives on the motion are shown for a simplified case.