Virtual Internet-based Sign Language Teaching Assistant (VISTA)

Not Available Hypersonic flight creates intense heating on the leading edges of aerostructures, thus mandating low-mass structures to accommodate the high temperatures generated by atmospheric drag and propulsion system exhausts. Even higher heat loads are imposed on structures heated by propulsion systems. Scramjet/airframe structures are exposed to heat fluxes as high as 10 Btu/in 2-sec. Typically, cooling is provided by liquid propellants. The combined coolant pressure and aerodynamic forces impose high structural demands. Performance goals require that these structures have low masses (<4 lb/ft2). Conventional materials and structures cannot meet these requirements. New materials and processes are available and can provide multifunctional structures to meet these challenges. Ultramet's innovative approach provides new methods of accommodating the weight and temperature challenges associated with hypersonic flight. The multifunctional structures to be evaluated in this project combine low-density, high temperature capability foam cores that function as both heat exchangers and rigid structural members. The open-celled foams would be closed out with tough ceramic or carbon composite layers, including high temperature oxidation and corrosion protection coatings as required. Also, for hydrocarbon-fueled hypersonic structures,: the foam core could eventually be evaluated with catalyst coatings that enhance decomposition of the endothermic fuel coolant, resulting in additional functionality.