Page 61 - European Energy Innovation - Summer 2015 publication
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Summer 2015 European Energy Innovation 61


technologies with a particular focus NOVA configuration with semi-buried engines for boundary layer ingestion
on engine integration options.
Four configurations have been aerodynamics (drag reduction) maximize boundary layer
designed by ONERA to explore and structure (wing root ingestion. Such radical engine
different possibilities for UHBR bending moment). integration with boundary layer
(Ultra High Bypass Ratio) engine ingestion is a real challenge
integration. NOVA is designed • Gull wing design to mitigate but it could enable significant
to carry 180 passengers on 3000 the drawbacks related to the fuel burn reduction. This is the
nautical miles (equivalent to an engine size, like compliance to reason why ONERA has been
Airbus A321) at Mach 0.82, and ground clearance limitations thoroughly investigating this
targets a 2030 entry-into-service. for instance. For under-wing concept, both numerically and
engines, the possibility of experimentally.
MAIN DISRUPTIVE modifying the wing dihedral
TECHNOLOGIES angle in its inner portion has This work funded by the French
NOVA aims at propulsive been investigated and led to a National Agency for Research
efficiency improvement and drag “gull-wing” shape. (ANR), allows ONERA to propose
reduction. To do so, it differs innovative solutions to the
from a conventional aircraft • Boundary layer ingestion: industry for an ever greener air
configuration by the following Aft fuselage mounted engines transport.
characteristics: have also been investigated,
conventionally podded, or Brought to our attention by Eucass. l
• UHBR Geared turbofan (GTF) semi-buried in the fuselage
engines (By-pass Ratio > 16, and thus ingesting the Boundary layer ingestion
compared to 10-12 for A320 boundary layer coming from
NEO). These engines are more the fuselage, for increased Contact details:
fuel-efficient and more silent, propulsive efficiency. ONERA – Applied Aerodynamics
but also larger and heavier, Boundary layer ingestion is an 8 rue des Vertugadins
so that their integration on opportunity to further reduce 92190 Meudon – FRANCE
the aircraft is a challenge. fuel consumption. It is more
Consequently the nacelle has efficient to produce thrust
to be shorter and thinner in by accelerating an already
order to mitigate its weight and slowed down flow such as
drag. Furthermore, for noise in a boundary layer, rather
reduction purpose, the nacelle than slowing down fresh air
inlet features a negative scarf before increasing even more
angle, which helps propagating its velocity. The engine will
sound waves upwards, away produce the same thrust
from the ground. with a reduced power. The
boundary layer is large on
• A wide lifting body of the aft part of the fuselage,
ovoid cross-section, made therefore semi-buried engines
of composite material. This are placed here in order to
fuselage, shorter and wider
than that of a conventional
single aisle, allows a 2-3-2
cabin layout in order to limit
turnaround time.

• A high aspect ratio wing with
downward-oriented winglets,
for a better balance between
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