Application of a CFD Moving -Body System to Multi component Store Separation *

Computational fluid dynamics (CFD) time-accurate trajectories were performed for a sequential release of two GBU-12s from an F-18C/D aircraft and compared to flight data. The computed trajectories were performed with full simulation of moving components of the store, which included moving canards and seekers as well as deploying fins. The motions of the stores and their components were controlled by the Fluid Dynamics-Computational Analysis of Dynamically Responsive Environments (FD-CADRE) system for moving-body simulations. The CFD solution was computed using NXAIR, grid assembly was performed using PEGSUS4, and the force-induced motions were computed using the Arnold Engineering Development Center (AEDC) six-degree-of-freedom (6DOF) code. Computed results compared well with flight data, which validated the process for computing trajectories for classes of stores with moving and deploying control surfaces. Additional time-accurate trajectories were performed to improve understanding of the uncertainties associated with current conventional ground-testing, analysis, and computational techniques. Finally, best practices designed for performing store separations for this class of weapons were documented.