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5 Supersonic Wind Tunnels
Fig. 5.16 Configurations of the nozzle of the ONERA S3MA wind tunnel (© ONERA)
to throat area. A nozzle with deformable walls allows a continuous variation of the
Mach number from 1.65 to 3.8 (see Fig. 5.17). Two sources of compressed air are
available; 9500 m
3 under a pressure of 9 bars and 115 m
3 under a pressure of 270
bars. A vacuum tank of 8000 m
3 at a minimum pressure of 0.010 bar is also available.
The total pressure of the wind tunnel can be varied from 0.2 to 7.5 bar depending
on the Mach number and the nozzle geometry. The air can be heated to a temperature
of 530 K by means of an electric heater. The maximum unit Reynolds number
achievable is 54 × 10
6 /m. The exhaust downstream is either to a vacuum tank or in the
atmosphere, depending on the Mach number. The blow-down time is between 10 s
and 15 min depending on the operating conditions and the evacuation mode (empty
sphere or atmosphere). Figure 5.18 shows the operational range of the S3MA wind
tunnel as a function of Mach number and total pressure with the curves of the constant
Reynolds number.
The S3MA wind tunnel has a very complete set of model supports (downstream
sting, lateral supports, masts, various specific devices) and many means of measurement and characterisation of the flow (steady and unsteady pressures, PSP, two and
three-dimensional LDV, various visualisation techniques, 6-component balances).
The tests typically performed in S3MA are; steady and unsteady force/moment
and pressures measurements on missile models, air intakes, optronic systems, wings
or helicopter rotor profiles.
5 Supersonic Wind Tunnels
Fig. 5.16 Configurations of the nozzle of the ONERA S3MA wind tunnel (© ONERA)
to throat area. A nozzle with deformable walls allows a continuous variation of the
Mach number from 1.65 to 3.8 (see Fig. 5.17). Two sources of compressed air are
available; 9500 m
3 under a pressure of 9 bars and 115 m
3 under a pressure of 270
bars. A vacuum tank of 8000 m
3 at a minimum pressure of 0.010 bar is also available.
The total pressure of the wind tunnel can be varied from 0.2 to 7.5 bar depending
on the Mach number and the nozzle geometry. The air can be heated to a temperature
of 530 K by means of an electric heater. The maximum unit Reynolds number
achievable is 54 × 10
6 /m. The exhaust downstream is either to a vacuum tank or in the
atmosphere, depending on the Mach number. The blow-down time is between 10 s
and 15 min depending on the operating conditions and the evacuation mode (empty
sphere or atmosphere). Figure 5.18 shows the operational range of the S3MA wind
tunnel as a function of Mach number and total pressure with the curves of the constant
Reynolds number.
The S3MA wind tunnel has a very complete set of model supports (downstream
sting, lateral supports, masts, various specific devices) and many means of measurement and characterisation of the flow (steady and unsteady pressures, PSP, two and
three-dimensional LDV, various visualisation techniques, 6-component balances).
The tests typically performed in S3MA are; steady and unsteady force/moment
and pressures measurements on missile models, air intakes, optronic systems, wings
or helicopter rotor profiles.