Aerodynamic characterization of noncircular cross-section missile configurations

Abstract

This article summarizes the computational efforts in the aerodynamic characterization of new missile configurations designed at the U.S. Air Force Academy that have either circular, or square, or triangular cross sections. These missiles were tested with and without strakes (low aspect-ratio fins) for different tail fin deflections and at a Mach number of 4.33 and a Reynolds number per length of 8.74 × 105 per inches. The triangular missile has a V-type fin arrangement. Cruciform (“+”) or cross (“×”) fin arrangements were tested for the square missile models. The simulations are performed for angles of attack in the range of [-4∘ – 15∘]. The aerodynamic force and moment coefficients were extracted from simulation data and compared with each other for different missile configurations and measured data. The effects of fin arrangement/deflections and strake geometries on the aerodynamic performance are investigated. The observed flow features are detailed including separated and vortical flows. The results show a very good agreement between predictions and measured data for all test cases and flow conditions. The missiles with triangular and square cross sections showed better aerodynamic performance than the circular model but they are less stable in the pitch direction.