Full Scale Wind Tunnel

PLENUM

The full-scale wind tunnel GIE S2A is a powerful way to test cars with all their real details. With its rolling road and boundary layer suction system to approach the actual conditions of the vehicle on the road, it is at the highest level of wind tunnel of this type in European or global level. It is used primarily to treat the aerodynamics of vehicles, about behavioral aspects and drag reduction, in direct link with the objectives of reducing consumption and CO2 emissions. The second use of the wind tunnel is the control of the noise sources related to the wind, with a view to improving passenger comfort. To address these two issues, it is equipped with all the necessary means to measure, especially a six-component balance to measure the aerodynamic forces, a pressure data acquisition system for aerodynamic measurements, and acoustic dummies, microphones and Beam-forming antennas for acoustic measurements.

It is an aerodynamic and aeroacoustic wind tunnel with:

• A 3/4 open jet test section

• A section of vein of 24 m2

• A maximum wind speed  of 240 Km / h

• A turntable to simulate the wind direction, with:

• A rotating belt between the wheels to simulate the moving ground (maximum speed: 200 km / h)

• Four drive wheels units (max speed: 200 km / h)

• A balance six components for the measurement of the torque aerodynamic

• An acoustic treatment on the walls of the test room and part of the air duct in order to perform noise measurements inside and outside vehicle

• An oculus, located at the rear of the turntable, to observe the underside of the vehicle

PLENUM
Tunnel	3/4 open
Nozzle section	24 m² (6,5 x 3,7)
Plenum length (between veils)	22,70 m
Plenum width (between veils)	16,20 m
Testing room length (between veils)	14 m
Plenum height	10,40 m
Max. WindSpeed	240 km/h
Contraction coefficient	6
Acoustic treatment	semi-anechoïc (Cut-off freq. = 125 Hz)
Background sound level (without wind)	< 44 dB(A) (~library)
Max nois level @160 km/h	69 dB(A) (~daytime street)
Control volume (ref=center of balance rotating plate)	-3 m < X < +3 m;
	-1,5 m < Y < +1,5 m
	-0,25 m < Z < +2,5 m
Flow charcateristics in the control volume
Flow uniformity @ 160 km/h	< 0,4 %
Angular deviation	< 0,6° plans XY et XZ
Turbulence rate	< 0,4 %
Longitudinal static pressure gradient along X axis (Y=0, Z=0.25 m)	< 0,001/m from -3m to +3m< 0,004/m from +3m to +5m
Boundary layer: displacement thickness	15 mm succion OFF, 7 mm succion ON
Tunnel
Tunnel dimensions	80,35 m x 38,60 m
Overall tunnel length	198,6 m

MAIN FAN

BALANCE