EFFECT OF NOSE BLUNTNESS ON HYPERSONIC UNSTEADY AERODYNAMICS

An analytic theory is presented that breaks down unsteady aerodynamic characteristics into local and nose-bluntness- induced components. Further, the theory uses experimental static data as an input, thereby including viscous-flow effects, and it correlates well with experimentally measured dynamic and static characteristics. By accounting for the time-lag effect associated with the translatory motion of the nose, when the oscillation center is not at the nose, this theory predicts the experimentally measured sharp decrease of damping accompanying increased static stability for stated values of base and nose bluntness diameter ratios.