Joint Services Store Separation Analyses for Joint Strike Fighter (F-35) Program with emphasis on Autonomous Weapon Systems
Acquisition of externally or internally mounted stores like missiles, bombs, and flares requires certification of the safety and acceptability of separation between aircraft and store. Ensuring that these stores detach safely and correctly from the aircraft is essential for achieving mission objectives. Often, the deployed missiles or bombs are equipped with control systems onboard to enable autonomous flights.
Two types of store separations exist: store jettison and employment. The distinction between the two lies in the activation status of the autonomous mode. Store jettison occurs when the autonomous mode is turned off or non-existent, while employment happens when the autonomous mode is activated during separation events. 
Store separation analysis is a critical component of the whole certification process. Store separation analysis can be a challenging and resource-intensive discipline, particularly for the internal weapons bay of the JSF. The JSF weapons bay is a highly stochastic and non-linear aerodynamic environment characterized by strong, unsteady aerodynamic gradients and non-repeatable store separation trajectories. Additionally, geometric constraints and model scaling prohibit the use of wind tunnel testing to properly measure the bay aerodynamics. The JSF program relies on resource-heavy unsteady computational fluid dynamics (CFD) to increase confidence in weapons bay analysis.
Despite the challenges, the CREATE CFD tool, Kestrel has been successfully applied to store jettison problems for both externally and internally mounted stores within JSF program by using HPCMP resources. However, its application to employment problems has been limited. This is attributed to the complexity of the employment problems, the lack of tools, and the availability of validation data. But it is now possible to extend and alter Kestrel’s functionalities with plugins. For example, it is possible to couple Kestrel with flight software. We propose to take the Kestrel plugin method to address employment problems alongside the common jettison problems.

F-35 JPO Public Release JSF25-0033. Distribution Statement A: Approved for public release: distribution is unlimited.
IMPACT
Significant efforts of the JSF Program Office (JPO) are being made to enhance the air dominance capabilities of the Joint Strike Fighter (JSF) by integrating new weapons and extending the flight envelopes of current weapons. The JPO CFD team has contributed by providing essential CFD data to support these efforts. In cases where there is a lack of adequate CFD data, it is likely that more conservative flight-testing methods will be suggested. This could lead to increased costs associated with test assets and longer durations for flight testing programs.
PRESENTER
Lee, Jae
jae.m.lee@us.navy.mil
703-477-5632
NAWCAD
CATEGORY
Comp Fluid Dynamics
SYSTEM(S) USED
Carpenter, Narwhal, Nautilus