Flight Performance and Dispersion Analysis for a Flexible Tactical Missile

Abstract

To deliver heavier payloads to longer ranges as the main objective of tactical missiles, higher slenderness and thrust-to-weight ratios are sought. This leads to the emergence of aeroelasticity, which can impact the accuracy of guided missiles and the accuracy and dispersion of unguided ones. The present study aims at exploring the effect of aeroelasticity on flight, dispersion, and accuracy of a case study tactical missile with about a 16.5 slenderness ratio. A framework is developed involving a flexible missile trajectory via -degree-of-freedom flight modeling, vibration characteristics estimation via the Euler–Bernoulli (EB) beam theory, aerodynamic characteristics estimation, and Monte Carlo simulation. Experiments are conducted to validate the EB theory and the aerodynamic model. A parametric study of the impact of missile flexibility and the roll rate on aeroelastic performance is conducted. The results show that missile deflection depends on the first bending frequency, and the static stability margin differs from that of the rigid one. It is also confirmed that aeroelastic divergence is introduced through the boosting phase. As the roll rate is introduced, higher aerodynamic frequency (and hence higher aerodynamic loads) is attained. Increasing the elasticity slightly reduces the missile downrange and yields precision improvement. Overall, the dynamic stability of the flexible missile increases as compared to that of the rigid case.