Activated
in 1976, the Hot Gas Facility (HGF) was redesigned
and reactivated in 1987. The HGF is a nominal
Mach 4.1 Aero-Thermal Tunnel that burns a lean
mixture of gaseous hydrogen and missile grade
air. Test conditions closely simulate flight
environments for heating rates, local pressure,
recovery temperature, and run duration. HGF
has been used for testing Solid Rocket Booster
(SRB) and External Tank (ET) thermal protection
system materials and configurations.
The HGF is a gaseous hydrogen/air combustion-driven
wind tunnel used primarily for thermal protection
system testing and aerothermal environments
definition. It can simulate aerodynamic heating
environments such as Space Shuttle ascent trajectories.
During a test combustion products are expanded
from the combustion chamber through a two dimensional
nozzle into a 16 in x 16 in x 40 in long test
section. A Mach 4 flow environment is induced
and from 3.5 to 25 btu/ft2/sec of convective
heating can be obtained.
The tunnel has been upgraded to include a 300kW
radiant heat system, a model insertion system
with varying wedge angles, and test section
shutter doors to protect the test article from
start up and shut down shocks. The IHGF radiant
heat system provides from 0 to 35 btu/ft2/sec
radiant and can be combined with the Mach 4
convective heat inputs for a world unique test
facility ideally suited for base heating environments.
Radiant-only heating with programmable vacuum
is also available.
All heating environments can be individually
profiled within the parameters of the facility
to follow a prescribed flight heating profile.
If requested, oxygen may be added to the combustor
flow to maintain 21% oxygen. The HGF also offers
thermal imaging support in order to provide
our customers with real time thermal response
and gradients of the test article. Test environments
can also be generated to follow a test article
temperature profile. The HGF can provide evaluation
of thermal performance, including recession
rates, heat transfer rates, temperature profiles,
and structural integrity.
Video of test articles can be recorded from
30 to 500 frames per second and high speed 16
mm movie film can record up to 10,000 frames
per second. Up to 72 channels of instrumentation
can be dedicated to each test article, with
more channels available upon request.
Hot Gas Test Parameters
Mach 4 Flow
GH2/Air Combustion-Driven
Convective, Conductive and Radiant Heating
0 - 25 degree angle of insertion for test
articles
Activated
in 1976, the Hot Gas Facility (HGF) was redesigned
and reactivated in 1987. The HGF is a nominal
Mach 4.1 Aero-Thermal Tunnel that burns a lean
mixture of gaseous hydrogen and missile grade
air. Test conditions closely simulate flight
environments for heating rates, local pressure,
recovery temperature, and run duration. HGF
has been used for testing Solid Rocket Booster
(SRB) and External Tank (ET) thermal protection
system materials and configurations. 
