Assessment of Technology for Aircraft Development

LMOST a decade ago, the National Research Council performed an invaluable study for the aerospace engineering discipline to project the technological needs for future advanced vehicle concepts. From the investigation for high-performance aircraft, four critical areas of the Aeronautical Technology 20001 were identified. The technology needs for future air vehicle design are in the following: efficient supersonic propulsion system, high-temperature composites/ metallic composite structures, high lift-to-drag ratio LID aerodynamics with efficient maneuvering lift, and reduced detectability. Although no single discipline encompasses all required technical areas, they are nevertheless not separable from each other. The anticipated requirement of composite or metallic composite structures lies in the heart of material research and structural dynamics. In this particular discipline, aerodynamics plays a coupling role to composite structures through aeroelasticity. For performance-limiting phenomena such as buffeting and flutter,2 aerodynamics either enters as an input for predicting the structural response to the dynamic load, or couples with the structural dynamics to provide the complete analysis for flutter. In the area of reduced detectability, the scientific issue rests on electromagnet ic theory, and the radar-cross-section analysis is governed by the Maxwell equations.3-4 Computational electromagnetics (CEM), the counterpart of computational fluid dynamics (CFD) in electromagnetics, has become a target of opportunity for technical transition.5"7 Numerous algorithms developed for supersonic flow simulation by solving the Euler equations are directly usable in CEM. The characteristic-based algorithms6"8 devised for shock-wave capturing are not only computationally efficient, but also have the potential of improving accuracy by alleviating spurious reflecting waves from the computational domain boundaries in