Cased Telescoped Ammunition Smart Seal Development

"Cased Telescoped Ammunition (CTA) has the potential to allow use of lighter ammunition-feed swing chambers, and more efficient ammunition storage, which will move the Army toward the lighter vehicles required by the Future Combat Systems (FCS) program.Technical obstacles have blocked the widespread application of CTA, particularly the sealing of propellant gases at the fore and aft of the cartridge during firing. MSI will extrapolate its experience in bioengineering applications with Nitinol shapememory alloys and other smart materials, and in design of seals for turbomachinery including aircraft gas turbine engines, using advanced computer-aided design analytical tools. In order to provide a tool for designing rings or sleeves which result inenhanced and reliable sealing, the coupled engineering problem will be attacked calculating the turbulent viscous leakage flow, acoustics, transient heat transfer, contact elasticity, and hyper-elastic (in the case of Nitinol) response. Physicalproperties required for the selected material (e.g. strain rate sensitivity of elastic modulus) will be verified by special testing by the material supplier. Three different conceptual prototypes will be manufactured to confirm their ability to take onconforming shapes, under elastic and/ or thermal loading, to enforce forward and aft sealing in a prototype 105 mm cartridge. Smart materials, particularly shape memory alloys, are applicable in many mil