Influence of spin rate on side force of an axisymmetric body

Results are presented for an experimental study in which a 10-deg half-angle pointed cone model 57.9 cm long and made of magnesium (for lightness and minimization of inertial effects) is spun at several rates about its axis of symmetry. The model is spun in both directions, but most of the data presented are for the counterclockwise rotation. The resulting side force is recorded on an oscillograph. It is shown that the side force observed occurs under conditions of spin about the longitudinal axis, and that the general shape of the side-force curve with roll position does not depend strongly on spin rate. However, the peak-to-peak value of side force decreases substantially with spin rate, suggesting that the vortices producing the side force require a significant amount of time to change position and/or strength.