As an example of the applicability of REL’s SABRE engine and heat exchanger technology to Mach 5 cruise, REL and the European Union
are exploring a new aircraft called LAPCAT. It would use the Scimitar pre-cooled engine - a derivative SABRE engine - which would allow
I
for commercial flights between Brussels and Sydney - a distance of 18,700 km (11,600 miles) in less than five hours. mage: Reaction Engines
and material tolerances to extreme
environmental variables are crucial
factors and the lightweight heat
exchangers appear to solve these
critical problems.
During 1989-2000 work focused
on the development of the
SABRE engine and the final Skylon
launch vehicle. Innovations in
aerothermodynamics, propulsion
and control technology attracted
a great amount of interest, private
investment and finally government
support.
The innovative carbon fibre
reinforced plastic fuselage for Skylon
provides a strong yet lightweight
airframe, surrounded by a single
skin of material, a ceramic external
aeroshell. This is corrugated for
stiffness and thermal compliance
on the substructure upon which
it
is
mounted.
A
thorough
research programme followed,
demonstrating the techniques for
full scale heat exchangers and the
manufacturing techniques to build
these components.
ESA independently reviewed the
work performed by Bond and REL
for the UK government, removing
any technical concerns and largely
validating Bond’s approach. In 2011
ESA reported the following to the UK
Space Agency:
“ESA are confident that a ground
test of a sub-scale [SABRE] engine
can be successfully performed to
demonstrate the flight regime and
cycle and will be a critical milestone
in the development of this program
and a major breakthrough in
propulsion worldwide.”
Return to flight
The UK government and the
UK Space Agency had removed
themselves
from
the
launch
technology game following the
Thatcher government’s notional
withdrawal from UK space efforts in
the 1980s.
However in early 2012, buoyed by
ESA’s recommendations, Bond and
REL began testing the first full scale
SABRE pre cooler with a jet engine to
test heat exchanger performance
in a working environment. This
demonstration pre-cooler included
over 50 kilometres of heat
exchanger tubing weighing less
than 50 kilogrammes and dropped
the air temperature to minus 150
degrees Celsius in 20 milliseconds.
In November 2012 REL announced
successful completion of the SABRE
engine tests with its pre-cooler heat
exchanger and ESA gave its official
validation of the results which was
backed up by the UK Minister for
Universities and Science David
Willetts.
Willetts has earmarked SABRE
and Skylon as a “high priority”
technology project and is working
with the UK’s Department of
Transportation to allow Skylon flights
within UK airspace. Bond himself has
said;
“These successful tests represent
a fundamental breakthrough in
propulsion technology. Reaction
Engines’
lightweight
heat
exchangers are going to force a
radical re-think of the design of the
underlying thermodynamic cycles
of aerospace engines. These new
cycles will open up completely
different operational characteristics
such as high Mach cruise and low
cost, re-usable space access, as
the European Space Agency’s
validation of Reaction Engines’
SABRE engine has confirmed.
“The REL team has been trying
to solve this problem for over 30
years and we’ve finally done
it. Innovation doesn’t happen
overnight. Independent experts
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