An Analysis of Steady Asymmetric Vortex Shedding from a Missile at High Angles of Attack

Abstract : Recent developments of highly maneuverable missiles capable of operating at high angles of attack have shown that large unexpected side forces and yawing moments occur due to asymmetric vortex separation from a slender missile body. The objective of the report was to develop a mathematical model which accounted for the viscous effects of the boundary layer fluid that sheds as discrete vortices, and to predict the forces and moments on a missile. An aerodynamic model in the crossflow plane based on von Karman's vortex street theory was developed. The number of vortex filaments which were shed and the positions of the filaments where determined from experimental data as a function of the crossflow Mach number. The Strouhal number was used to relate time in the crossflow plane with time to travel along the missile.