Hypervelocity Aerodynamic Interaction of Ballistic Bodies

ABSTRACT: CFDRC proposes to develop a high-fidelity simulation capability and probabilistic description for the unguided dispensing of submunition projectiles from weapons systems. The proposed technology will be based on the Loci/CHEM software framework. In the Phase I effort, a rigid body collision module for Loci/CHEM was developed and the accuracy and scalability of the proposed technology was successfully demonstrated for multiple projectiles in proximate flight at supersonic speed. The Phase II effort will focus on a) full implementation of the coupled simulation capability, b) application demonstrations for capturing dominant influence factors in the dispersion process, and c) development of a design-of-experiment methodology to deliver probabilistic projectile state definitions with reasonable computational effort. The resulting probabilistic definition of projectile spatial distribution and flight state will be employed to investigate optimal deployment strategies, and recommendations will be made for achieving even projectile distribution patterns over a target area. This Phase II effort will enable high-fidelity simulations of large number of bodies in high-speed proximate flight with optimal parallel scalability, and provide the means to reduce the complexity by introducing a probabilistic model to describe the aerodynamic interference-dominated phase. The culmination of these efforts will enable radical reduction in CPU requirements and design cycle time over existing approaches. BENEFIT: Military Application: The resulting simulation capability will enable design and evaluation of technology and concept maturation for safe dispensing and pin-point delivery of payloads. It will support integration design of submunition and ordnance ejection processes for hypersonic and lower Mach airframes. Other military applications include modeling and simulation of multiple store separation and dispensing from wing or weapon bay platforms to support store certification efforts, simulation of debris/fragments trajectories resulting from accidental explosions or planned missile intercept. Commercial Application: The predictive capabilities will benefit system design and process planning for air delivery of payloads such as humanitarian relief supplies. The methodology will help predict payload ground-impact distributions for flight regimes intended for commercial applications.