Many aircraft need to operate efficiently at more than one flight regime; for example, certain airframes are expected to perform in relatively high-speed cruise modes, as well as slower loitering scenarios. Unfortunately, an engine operates most efficiently when the exit velocity closely matches the speed of the...

Innovators at the NASA Armstrong Flight Research Center have developed a compressor-generator-motor turbojet design concept that integrates the generator with the aerodynamic blade structures of the compression section of turbomachinery. This reduces weight and volume...

Thermosetting reactive resin systems such as epoxy, bismaleimide, and polyimide classes of material are brittle. The origin of brittleness is attributed to the high crosslinking density that exists in the fully cured forms of these materials. Traditionally, the toughness of these resins is...

The Northwest Research Associates (NWRA) Aircraft Vortex Spacing System (AVOSS) Prediction Algorithm computes trailing vortex trajectories and circulation decay in a plane perpendicular to the path of the aircraft that has generated the vortices. Underlying the algorithm are the following...

NASA's Langley Research Center has developed an optical method for detecting displacements and strains at ultra-high temperatures during thermo-mechanical testing. This innovation will provide displacement and strain measurements in...