6.3 Hypersonic “Hot” or Hyper-enthalpic Wind Tunnels
159
(a) Test section
(b) Test tube installed in the test section
Fig. 6.32 Test facility COMETE of Airbus Safran Launchers (© ASL)
torches to heat air, an air-argon mixture, or another gas such as N 2 –CO 2 mixture that
simulates the conditions of re-entry to Mars.
The COMETE test facility is a low power facility that uses an inductively generated plasma (electromagnetic waves are used to ionise the air) while the plasma
torch being placed in an instrumented vacuum chamber (see Fig. 6.32a).
Models facing the generator outlet are subjected to hot flow over long periods of
time (see Fig. 6.32b). The main features of the COMETE facility are:
– electrical power of 75 kW,
– stagnation enthalpy greater than 8 MJ/Kg (air),
– test duration ranging from a few seconds to 30 min,
– air, argon or nitrogen as operating gas,
– diameter of the subsonic jet of 80 mm,
– diameter of the tested articles of 50 mm.
The stresses subjected by the test articles vary from 30 to 400 mbar in pressure
and from 300 to 3000 kW/m
2 in heat flux (cold wall conditions) under subsonic
conditions.
The second technology is based on Huels-type arc heater and operates according
to the schematic shown in Fig. 6.33. An electric current is sent into the upstream
electrode and is transferred through the gas to a hollow downstream electrode through
which the fluid flows. An external magnetic field is applied to rotate the arc foot and
thus limit the erosion of the electrodes, the walls being cooled by a water circuit.
The SIMOUN, another test facility of ASL shown in Fig. 6.34, operates on a
plasma torch principle generated by an electrically driven pneumatic and hydraulic
system.
At the outlet of the plasma generator, a nozzle accelerates the plasma in order to
generate representative conditions for model testing. A vacuum chamber allows high
flow rates while the gases are being exhausted through a diffuser downstream of the
test chamber. The square test chamber is instrumented with various optical means
159
(a) Test section
(b) Test tube installed in the test section
Fig. 6.32 Test facility COMETE of Airbus Safran Launchers (© ASL)
torches to heat air, an air-argon mixture, or another gas such as N 2 –CO 2 mixture that
simulates the conditions of re-entry to Mars.
The COMETE test facility is a low power facility that uses an inductively generated plasma (electromagnetic waves are used to ionise the air) while the plasma
torch being placed in an instrumented vacuum chamber (see Fig. 6.32a).
Models facing the generator outlet are subjected to hot flow over long periods of
time (see Fig. 6.32b). The main features of the COMETE facility are:
– electrical power of 75 kW,
– stagnation enthalpy greater than 8 MJ/Kg (air),
– test duration ranging from a few seconds to 30 min,
– air, argon or nitrogen as operating gas,
– diameter of the subsonic jet of 80 mm,
– diameter of the tested articles of 50 mm.
The stresses subjected by the test articles vary from 30 to 400 mbar in pressure
and from 300 to 3000 kW/m
2 in heat flux (cold wall conditions) under subsonic
conditions.
The second technology is based on Huels-type arc heater and operates according
to the schematic shown in Fig. 6.33. An electric current is sent into the upstream
electrode and is transferred through the gas to a hollow downstream electrode through
which the fluid flows. An external magnetic field is applied to rotate the arc foot and
thus limit the erosion of the electrodes, the walls being cooled by a water circuit.
The SIMOUN, another test facility of ASL shown in Fig. 6.34, operates on a
plasma torch principle generated by an electrically driven pneumatic and hydraulic
system.
At the outlet of the plasma generator, a nozzle accelerates the plasma in order to
generate representative conditions for model testing. A vacuum chamber allows high
flow rates while the gases are being exhausted through a diffuser downstream of the
test chamber. The square test chamber is instrumented with various optical means