Prediction of Ballistic Separation Effect by Direct Calculation of Incremental Coefficients

Abstract

The ballistic separation effect in an aircraft flowfield was predicted via the direct calculation of incremental coefficients. A highly robust flow solver, including a Chimera grid module, was used to create the trajectory of a released store and to calculate incremental coefficients. The incremental coefficients were computed according to the difference between the aerodynamic coefficients in the aircraft flowfield and in the freestream condition. Two different calculations can be executed simultaneously in a parallel computing environment. The aircraft flowfield effect was measured using the incremental coefficients. This method of direct calculation of the incremental coefficients was tested in the case of released stores in two-dimensional subsonic and supersonic flow regions. The accuracy of the unsteady trajectory calculation was verified through comparisons with the captive trajectory system data in the Eglin wing/pylon/store separation problem. The method was then applied to a generic bomb released from a full-body aircraft. The computational results show that the current method is capable of simulating the store trajectory and investigating aircraft flowfield effects.