Towards High Efficiency Hypersonic Flight – Hypersonic Bi-Directional Flying Wing

This paper examines the use of a hypersonic bi-directional flying wing concept for use in a high efficiency hypersonic system. The bi-directional flying wing concept consists of a symmetric planform which enables flight to occur at two different geometric configurations. The subsonic configuration would have a high aspect ratio and a low sweep. The aircraft would then rotate 90 degrees and enter the hypersonic configuration which would have a low aspect ratio and high sweep. This design overcomes the inherent conflict between subsonic and hypersonic flight in conventional hypersonic systems. The design was found to have high aerodynamic efficiency at both hypersonic and subsonic speeds. This concept could be applied to civil transports and military vehicles alike as the subsonic mode allows the aircraft to be operated on conventional runways. This paper examines some of the unique challenges that would be present in a hypersonic civil transport because of the need to ensure passenger comfort and safety. Optimization of the design is dependent on high speed multi-mode engines and high temperature resistant materials.