Achievements obtained within the European LAPCAT program

23 NOV. 2005 14167

General outline

The baseline mission requirement of LAPCAT is to reduce travelling time of long-distance flights, e.g. Brussels to Sydney, in about 2 to 4 hours. This requires a new flight regime with Mach numbers ranging from 4 to 8. At these high speeds, classical turbo-jet engines need to be replaced by advanced airbreathing propulsion concepts and hence related technologies need to be developed.

Key objectives are the definition and evaluation of different propulsion cycles and concepts, enhancement of integrated engine/aircraft performance, mass-efficient turbines and heat exchangers and finally high-pressure & supersonic combustion experiments and modelling.

Though the project is mainly technology driven, operational conditions and constraints are defined by several conceptual vehicle designs of which three are highlighted in our Experiments and modelling webpage which can be seen from the right hand navigation bar.

The LAPCAT A2 vehicle flying at Mach 5 was carried out by Reaction Engines. The vehicle study indicates that a 400ton, 300 passenger vehicle could achieve antipodal range without marginality. The concept is particularly interesting for this mission requirements as a trajectory optimization allowed to fly almost continuously over sea and avoiding sonic boom impact when flying over land. The vehicle relies on pre-cooled turbo-based engines employing a cycle based on the Reaction Engines SABRE spaceplane engine.

B. Kerosene Mach 4.5 Cruiser

A parallel study carried out by DLR-Sart focused on kerosene as a fuel in order to explore the performance of this fuel in preference to hydrogen since its supply infrastructure is well established. In order to keep the wing loading in an acceptable range, the new supersonic cruise airplane has a wing size of 1600m2. The total length reaches 102.78m which is only slightly longer. The LAPCAT-M4 employs a blended wing-body with a modified nose, a highly swept in-board wing panel, and a moderately swept outboard wing panel. The four advanced turbo-RAM-jet Variable Cycle Engines (VCE) are mounted in two nacelles on the wing lower surface adjacent to the fuselage.

C. Hydrogen Mach 8 Cruiser

The vehicle-propulsion integration proved to be a difficult exercise for the higher flight Mach numbers. The aim was to ensure a good aerodynamic performance for both subsonic and hypersonic speeds along with a large volume for hydrogen fuel, an efficient propulsion unit for the acceleration phase with enough thrust and finally, realistic dry and gross take-off weights. An air turbo-rocket is used for the acceleration phase until M=4 while a dual mode ramjet propulsion unit was used for the final acceleration and cruising at Mach 8. This optimization loop resulted into the LAPCAT-MR1 vehicle with a dorsal placement of the propulsion unit, including the large intake ramp and nozzle. The aerodynamic performance was realized by using a blend of a waverider and a delta wing previously developed by DLR-Braunschweig. The aircraft turned out to be a versatile and operationally flexible vehicle. The GTOW was fixed at 600tons which corresponds to the present achievement in classical aircraft, e.g. the Antonov-225 with a 600 to 640tons GTOW and a 170tons of empty mass.

LAPCAT-MR1: Left: Conceptual Design of a Dorsal-Type Mach 8 vehicle: blue indicates the passengers’ area, other colours define different fuel tank shapes. Right: Geometrical comparison with the A-380 and An-225. (courtesy ESA)

Linkuri similare

[ Space Engineering & Technology ]

09 DEC. 2008

Experiments and Modelling

For high-speed transportation vehicles powered by air-breathing engines achieving a positive aero-propulsive balance is crucial for the success of the whole system. No ground facility in the world allows testing a real sized vehicle under flight conditions including operating engines. The potential of the CFD tools for ground to flight extrapolations is coming on request. However, dedicated experiments are clearly needed to evaluate and check the validity of the CFD-tools for combustion and aerothermodynamics.An air inlet representative of the LAPCAT Mach 8 vehicle has been designed in accordance to geometric constraints driven by the vehicle and to requirements of the flow at the inlet exit stemming from the combustion chamber. The intake has been studied experimentally and by using large-eddy simulations.

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[ Space Engineering & Technology ]

23 NOV. 2005

LAPCAT I overview

Long-Term Advanced Propulsion Concepts and TechnologiesTo reduce the travelling time of long-distance flights, e.g. Brussels to Sydney, in about 2 to 4 hours, advanced propulsion concepts and technologies need to be developed. This requires a new flight regime with Mach numbers ranging from 4 to 8. At these high speeds, classical turbo-jet engines need to be replaced by advanced airbreathing engines.

Citește articolul

[ Space Engineering & Technology ]

12 MAR. 2008

Facts and figures

LAPCAT is a 'Specific Targeted Research Project' (STREP) supported by the European Commission through the 6th Framework under the Thematic Priority 1.4 'Aeronautics & Space'.

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