Physics-based, Fast-Running Tool for Fuel Spurt Modeling from HRAM

ABSTRACT: CFDRC propose the development and validation of a physics-based, fast-running tool to quantify fuel spurt timing, volume, and droplet size from impact on fuel tanks. In Phase I we will develop models that will capture the critical physics of each sub-phase of HRAM, i.e. projectile dynamics including tumbling, cavitation, its growth and collapse, high pressure pulses, and spray atomization. This will be accomplished by adapting an existing multiphysics and multiphase fluid-structure interaction code and by validating against available and new experimental data provided by our experimental partner. Also in Phase I, we will improve the simulation efficiency through developing a reduced order model for each phase of HRAM. Our approach not only represents the real physics, but also enables the simulation of different threat and tank characteristics. Phase II will fully develop the simulation tool demonstrated in Phase I, and will conduct controlled experiments to quantify the fuel spurt. The refined tool will be validated on typical fuel tank with internal stiffening structure and clutter components as encountered in aircraft. Various model reduction technologies will be used to improve computational efficiency while maintaining the required accuracy of at least 90%. Additionally, an appropriate interface module will be developed to interface the simulation tool with various simulation environments at the Air Force. BENEFIT: The successful completion of this SBIR will provide the Air Force and DoD with the capability for rapidly evaluating fire ignition in complicated aircraft (and other vehicle) dry-bays and compartments under various HRAM scenarios. Although most past efforts have been aimed at protecting military aircraft, the developed tool also finds many applications in commercial aircraft, which are at risk due to high velocity fragments produced by engine failure, or even runway debris as in the case of Concorde 203 F-BTSC that crashed after takeoff from Paris. Another application is in the venerability assessment of Space Launch Systems under development at NASA, which use cryogenic liquid fuel. The fast-running and high-fidelity code can be commercialized for applications in all commercial and military air, ground, and sea vehicles that have fluid-filled fuel tanks.