Aviation and the Global Atmosphere

Aviation and the Global Atmosphere
between an MD-11, BWB, and conventional 800-passenger aircraft is shown in Figure 7-6
(Liebeck, et al., 1998). Studies have assessed the potential of the BWB design. The advantage
of the BWB over conventional or evolutionary designs stem from extending the cabin spanwise,
thereby providing structural and aerodynamic overlap with the wing. This design reduces the
total aerodynamic wetted area of the airplane and allows a higher span to be achieved because
the deep and stiff centerbody provides "free" structural wingspan. Relaxed static stability allows
optimum span loading. If engine and structural material technologies remain the same for the
BWB, initial estimates show that fuel burn could be reduced significantly relative to that of
conventionally designed large transports (Liebeck et al., 1998). Other large transport
configurations are being evaluated (McMasters and Kroo, 1998) and compared to current
designs.
In addition to the fuel burn and emissions reduction potential of this concept, the engine
installation and airframe can help to minimize exterior noise: Inlets are placed above the wing so
fan noise is shielded by the vast centerbody.
Validation of potential fuel burn benefits will require extensive full-scale testing. The principal
challenges lie in the overall structural integrity of the oval pressure vessel, integration of
propulsion and airframe, emergency egress (evacuation of passengers on land and water),
passenger acceptance, and airport compatibility. An initial BWB concept could enter service after
the year 2020. However, the passenger size and range of the initial design is not known at this
time.
Table of contents | Previous page | Next page
Other reports in this collection
http://www.ipcc.ch/ipccreports/sres/aviation/094.htm (4 von 4)08.05.2008 02:43:24
Figure 7-7: Gas turbine schematics.
IPCC Homepage