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number, Reynolds number, and size
for the aerodynamic configuration,
and mixing studies needed up to
Mach number 10.
A facility is needed to generate
detailecl experiments for compu-
tational validation and engineering
design data for complex configur-
ations, under conditions where the
effects of cold walls, roughness,
and flow field disturbance charac-
teristics can be evaluated. Such a
facility could provide the connec-
tion between the stratospheric
disturbance field (yet to be
measured and modeled) with the
wind tunnel data shown to be
sensitive to this parameter.
4) We recommend that the highest
priority be placed on the design,
construction, and operation of a
"quiet" wind tunnel in the Mach
number range of 10, with a scale
and Reynolds number capability to
permit flight simulation. An
expeditious approach may be the
conversion of an available facility
with the required operating condi-
tions, such as the AEDC Gas
Dynamics Facility.
3.4.2 High Hypersonic Speeds (M > 10)
5~ For these conditions, the require-
ment is a simulation of BOTH the
aerodynamics (viscous and flow
field described at low M) and the
real gas effects including chemical
non-equilibrium effects. High
Reynolds number continuum flow to
the high free molecular region must
be understood and predicted.
6) No current facility or facilities can
cover the complete range of flow
parameters with the flow quality
(mean distribution, constituent and
density determination, and flow
field disturbance field) needed, and
HYPERSONIC TECHNOLOGY FOR MILITARY APPLICATION
this lack will be an important
detriment to the generation of
engineering design data.
Existing and proposed facilities,
such as arc tunnels, MHD acceler-
ators, shock tunnels, and flight
ranges, each have some potential to
generate the required data, but all
have significant limitations.
S) CFD needs validation data, but it
appears that it must be done in
elements since no full simulation of
high hypersonic speeds is available
or within sight in ground test
facilities. For this reason, flight
tests will be necessary for full
validation of CFD codes.
9)
The full characteristics of the flow
fields generated by present facil-
ities are incomplete and not yet
matched to the requirements of
CFD for specific validation exper-
iments, although the technology is,
in many cases, within reach.
10) We recommend a combined CFD
experimental program focused on
key hypersonics aerodynamic
elements to provide validated units
for combination into realistic
configurations at flight conditions
that can be reached by ground
facilities.
1 1 ) We recommend that the field of
low density flows be given special
attention with regard to direct
simulation of particulate flows and
experimental validation. This would
provide much needed information on
high altitude, high Mach number
flight conditions where continuum
Navier-Stokes computations are of
uncertain accuracy. The applica-
tion of the aerodynamic studies,
both computational and ground-
based, will require detailed
knowledge of the characteristics of
the stratosphere to translate the
Representative terms from entire chapter:
design data
