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OCR for page 85
FINDINGS AND RECOMMENDATIONS
research results into engineering
data.
Real gas reaction and recombination
rates for all constituents and flight
conditions are required. Many of
these rates are known at low tem-
peratures and extrapolation to
higher temperatures appear to be
within reach of computational
chemistry.
13) We recommend a national integrated
program of high priority to provide
these rates for inclusion into CFD
computations. The NASA Ames
Group provides a key nucleus for
such an effort.
3.5 Controls, Guidance, Instrumentation
and Information Processing 9)
1) No successful hypersonic engine or
airframe will be possible without
multi- redundant, multi- effecter
active control of aircraft rigid,
structural, and slosh modes; aircraft
and propulsion system; and thermal
effects.
2) Information and controls must join
aerodynamics, structures, materials,
and propulsion as a central and
enabling technology
3) Control challenges for hypersonic
aircraft are well beyond any
previous accomplishments, in terms
of overall aircraft and propulsion
system integration, in the required
precision, and at subsystem levels
(e.g., engine, thermal)
4) Very high throughput, fault-tolerant
control is essential to meet the
unprecedented combined require-
ments for throughput and reliabil-
ity.
5) Essential hypersonic flow sensors
for airplane and engine controls do
61
not exist.
6) Control actions have the potential
to reduce the sensitivity of engine
characteristics to uncertainties and
fluctuations, however just what to
control, either directly or as a
surrogate, to achieve these benefits
is not well known, and appropriate
sensors may not be available now.
The hypersonic thermal environment
challenges the capability of existing
electronic and hydraulic technology.
S) A phased flight program, with asso-
ciated phased flight control system
configurations that gradually work
up the speed envelope, is necessary
to reduce controls risks.
Three parallel actions are recom-
mended to reduce the risks
involved with this technology area:
a.
b.
c.
Aggressive technology matur-
ation efforts in control system
architecture (feedback system
structure) and associated analy-
sis/synthesis activities to cope
with the novel flight, engine,
and thermal control needs.
System studies into hardware
and software as needed to
assure the availability of
adequate controls and
· -
assoclatec . equipment.
Efforts to define earlier (than
X-30 flight) experiments that
can be done to at least par
tially validate the equipment
and techniques prior to com
mitment to hypersonic flight.
Flight tests at lower speeds on
other aircraft should be con
sidered a well as laboratory
and simulation-based testing.
These actions should focus on all aspects
of control: subsystem control, integra-
tion of systems, reduction of sensitiv-
ities, control/information system archi
Representative terms from entire chapter:
integrated program
