Store Release Trajectory Variability from Weapon Bays Using Scale-Adaptive Simulations

In this paper, scale-adaptive simulation is used to study store trajectory variability for releases from transonic weapon bays. The scale-adaptive simulation captures the essential physics of the flow in the weapon bay, and its speed of computation allows for several trajectories to be computed within reasonable time. The results of the simulations are treated as a statistical set and a metric is put forward to decide the minimum number of simulations necessary to establish the mean and the standard deviation of the releases. Averaging the results of all trajectories was useful in developing an overall understanding of the bay pressure field role on the store trajectories. Filtering the obtained trajectories provided insight in the flow frequencies affecting the forces acting on the store and the coordinates of its center of gravity during releases. For the store employed in this study, less than one month of CPU time is needed for the complete set of simulations to be obtained, making this method promising as a further test before flight testing.