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MODELLING: AEROSPACE
Turbulence studies, such as finding the laminar-turbulence transition, are critical to evaluating an aircraft wing’s angle of attack and the overall
performance (image courtesy of EADS Germany GmbH – Military Air Systems).
fan’s high suction prevents flow
‘That firm initially used what company
results helped optimise the
from separating off the wing. blade and housing geometry.
The result for a given wingspan
president Joe Kummer refers to as the
Other studies looked at the
is as much as 10x the payload
“poor man’s infinite wind tunnel” – strapping
effect of propulsive airfoil design
and 3x the lift of conventional
an early three-foot prototype to the roof of
parameters – for example fan
aircraft. It can also maintain an speed and sizing, duct inlet and
extreme angle of attack, 40 to 45
a minivan and driving down country roads’
outlet locations, and exhaust
degrees, without stalling. And angle – on lift, drag and pitching
while the aircraft can’t hover, Stability and control were an alters the pressure distribution moment.
its forward speed at landing enormous challenge in this very on the wing surface while
can be quite slow, meaning highly coupled system notes creating a nose-up reaction due Taming turbulence
shorter runways. This past Kummer, who adds that without to the direction of rotation. Although the underlying
summer the company created CFD the plane as it is wouldn’t Using Star-CCM+ software, equations that define the physics
flying prototypes, made its first exist. A higher fan speed Propulsive Wing was able to of how aircraft work have been
formal presentation to the increases the flow rate; the result successfully understand these well known for many decades,
aerospace industry at the CD- is not only higher thrust but, relationships and create a stable how these equations are applied
adapco StarGlobal Aerospace, depending on the exhaust angle, aircraft. continues to undergo
Defense and Marine Forum in it changes the aircraft’s pitch-up/ CFD was also used extensively considerable refinement. Several
September, and is looking for down tendency. Simultaneously, to simulate sub-systems. In the interesting examples come from
partners to commercialise the the fan also produces greater design of the cross-flow fan Ansys, says Brad Hutchinson,
technology. suction at the air inlet, which propulsion system, simulation VP of industry marketing, ➤
www.scientific-computing.com SCIENTIFIC COMPUTING WORLD october/november 2009
45
SCWoct09 pp44-47 aerospace.indd 45 10/2/09 4:37:38 PM
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