Aerospace & Defense Technology - December 2024 - 27

Tech Briefs
" If you can learn how to predict those
frequencies, then our method can give
you some prediction of what is headed
your way, " says Gharib, who is also Director
of the Graduate Aerospace Laboratories
at Caltech.
" Fourier methods work well here
because turbulent waves are better
modeled in terms of frequencies, with
most of their energy lying in low frequencies, "
says co-lead author Sahin
Lale (PhD '23), now a Senior Staff
Research Engineer at Neural Propulsion
Systems, Inc., who completed the
work while at Caltech. " Using this
prior knowledge simplifies both the
learning and control of turbulent
dynamics, even with a limited amount
of information. "
To test the effectiveness of the FALCON
strategy, the researchers created an
extremely challenging test setup in the
John W. Lucas Wind Tunnel at Caltech.
They used a fully equipped airfoil wing
system as their representative UAV, outfitting
it with pressure sensors and control
surfaces that could make adjustments
online to things like the system's altitude
and yaw. They then positioned a large cylinder
with a moveable attachment in the
wind tunnel. When wind flowed over the
cylinder, it created random, major fluctuations
in the wind reaching the airfoil.
" Training a reinforcement learning
algorithm in a physical turbulent environment
presents all kinds of unique
challenges, " says Peter I. Renn (BS '19,
PhD '23) co-lead author of the paper
who is now a quantitative strategist at
Virtu Financial. " We couldn't rely on
perfectly clean signals or simplified flow
simulations, and everything had to be
done in real time. "
After about nine minutes of learning,
the FALCON-assisted system was
able to stabilize itself in this extreme
environment.
" With each new observation, the program
gets better because it has more
information, " says Anandkumar.
This article was written by Kimm
Fesenmaier, Content and Media Strategist,
California Institute of Technology
(Pasadena, CA). For more information,
contact Kimm, at kfesenma@
caltech.edu.
'First of Its Kind' Composite Material to Help Space
Vessels Travel Longer Distances
A Coventry University design and materials engineer is leading an international team of researchers in the
creation of a new material for liquid hydrogen storage tanks that are used to propel rockets into space.
Coventry University, Coventry, UK
T
he future of space travel is seemingly
changing by the day and a Coventry
University academic is doing his bit to
stay at the front of the space race.
Dr. Ashwath Pazhani along with an
international team of researchers have
created a new material for storing the liquid
hydrogen used to propel rockets into
space by the likes of NASA.
AA 2900
Their new material is lighter than the
current material used for liquid hydrogen
storage tanks and means that more fuel
can be stored or more payload carried at
one time - a feat that Dr. Pazhani
describes as a " groundbreaking work that
leapfrogs current research in the field " .
" This all started as I was looking for
the super lightweight and load-bearing
Novel Powder Mixture of AA 2900
+ 2D-Grnp
Power Meter
Runway
Temperature
Hydraulic Pump
On/Off Switch
2D-Grnp
Ar
Runway Pour
On/Off Switch
Squeeze
Press/Release
Switch
Stirrer
On/Off
Switch
Stirrer
Stirrer
Speed
Controller
Bottom Pouring
Attachment
Bottom Pouring
Controller
Die
Up/Down
Switch
Runway
Preheater
Gas
Squeeze Pressure
Indicator
Mains
Motor
Reinforcement Preheating
Chamber
Thermocouple
Melt
Temperature
Electrical Resistance
Furnace
Inert Gas
Hydraulic
Press
material for external fuel tanks. The
material in question has been used since
1993 to store liquid hydrogen and yet in
this work we innovatively reinforced this
material with nano graphene, creating a
new composite out of that, " said Dr.
Pazhani, Lecturer in Engineering Design
and Materials Specialism. " We have been
able to reduce overall external tank
Schematic illustrating the powder processing of the novel mixture and the production of the 2D-Grnp/AA 2195 MMC via the stir/squeeze casting process. (Image:
Coventry University)
Aerospace & Defense Technology, December 2024
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Aerospace & Defense Technology - December 2024

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