21st Congress of International Council of the Aeronautical Sciences, Melbourne, Australia, 13-18 September, 1998
Paper ICAS-98-1.3.1

OPTIMAL THREE-DIMENSIONAL RANGE CRUISE OF A DUAL-FUEL HYPERSONIC VEHICLE

Mayrhofer M., Dinkelmann M.*, Sachs G.
Technical University of Munich, Germany; *DASA, Germany

Keywords: dual-fuel, hypersonic vehicle, range optimization

The optimization of the overall cruise trajectory of a two staged dual-fuel hypersonic flight system with in-flight refueling of the carrier stage is subject of this paper. The flight system performs a range cruise until separation after which the carrier stage equipped with an air breathing powerplant (turbo and ram jet engines combination) re turns to its launch site. The rocket propelled orbital stage conducts an ascent to nominal orbit. The performance requirement for the carrier stage is to reach any latitude on the northern hemisphere from a launch site in Southern Europe. A promising approach for attaining such an extreme performance goal is the dual fuel concept. This concept basically employs kerosene and liquid hydrogen of which kerosene is used for the turbo jet engines in subsonic and supersonic flight while hydrogen is applied for the ram jet engines in the hypersonic region. The use of kerosene provides an in-flight refueling capability which is not possible with an all-hydrogen-propelled vehicle because of safety reasons. Investigations were made for one, two and three in-flight refuelings. In the case of three in-flight refuelings it is possible to reach the equator from a start point at 43.5° latitude. Thus. It is possible to attain every latitude on the northern hemisphere.

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