Chapter 3
Subsonic Wind Tunnels
3.1 Subsonic Wind Tunnels for Aeronautics
3.1.1 Historical Subsonic Wind Tunnels in France
Built by Gustave Eiffel, and still in use, the low speed wind tunnel at the Scientific
and Technical Centre for Building (CSTB) located in Auteuil was inaugurated on 19
March 1912 (see Fig. 2.1). Figure 3.1 shows Gustave Eiffel and his colleague Léon
Rith in the wind tunnel control room.
This installation is a transfer of the first wind tunnel, installed in 1909 at the foot
of the Eiffel Tower, in the Champs-de-Mars. Initially it achieved a velocity of 18 m/s
in a circular test section of a diameter of 1.5 m and was driven with a fan powered
by a 37 kW motor. With the same motor, during the re-installation at Auteuil the
new facility was equipped with a diffuser and allowed the tunnel to reach 32 m/s (an
increase of 78% of the velocity) in a test section of a diameter of 2 m, resulting in
a mass flow gain of over 200% (see Fig. 3.2). This marked the birth of the diffuser
which was a major improvement in wind tunnel design and helps to increase the
speed at which they could be operated by offering a recovery in pressure.
The wind tunnel is still used for industrial aerodynamics studies, wind effect on
buildings, aeroacoustic and other aerodynamic applications as shown in Fig. 3.3.
Although no longer in service, as an introductory remark it is interesting to briefly
describe this typical very large facility inaugurated in 1935 on the site of ChalaisMeudon and originally designed for full scale aircraft testing. Figure 3.4 shows an
aerial view of the wind tunnel. Of the Eiffel type, this wind tunnel has a contraction
ratio of 3.5 with an inlet of 100 m
2 at the beginning of the working section. The
collector captures the air from outside the facility through a large plenum which is
then accelerated to a maximum speed of 45 m/s. The exit of the open jet test section
has an elliptical shape with a 16 m major axis and an 8 m minor axis. Its diffuser
consists of a truncated cone-shaped tube with a length of 38 m, made of 70 mm thick
reinforced concrete. Downstream of the diffuser, the suction chamber is equipped
© Springer Nature Switzerland AG 2020
B. Chanetz et al., Experimental Aerodynamics,
Springer Tracts in Mechanical Engineering,
https://doi.org/10.1007/978-3-030-35562-3_3
51
Subsonic Wind Tunnels
3.1 Subsonic Wind Tunnels for Aeronautics
3.1.1 Historical Subsonic Wind Tunnels in France
Built by Gustave Eiffel, and still in use, the low speed wind tunnel at the Scientific
and Technical Centre for Building (CSTB) located in Auteuil was inaugurated on 19
March 1912 (see Fig. 2.1). Figure 3.1 shows Gustave Eiffel and his colleague Léon
Rith in the wind tunnel control room.
This installation is a transfer of the first wind tunnel, installed in 1909 at the foot
of the Eiffel Tower, in the Champs-de-Mars. Initially it achieved a velocity of 18 m/s
in a circular test section of a diameter of 1.5 m and was driven with a fan powered
by a 37 kW motor. With the same motor, during the re-installation at Auteuil the
new facility was equipped with a diffuser and allowed the tunnel to reach 32 m/s (an
increase of 78% of the velocity) in a test section of a diameter of 2 m, resulting in
a mass flow gain of over 200% (see Fig. 3.2). This marked the birth of the diffuser
which was a major improvement in wind tunnel design and helps to increase the
speed at which they could be operated by offering a recovery in pressure.
The wind tunnel is still used for industrial aerodynamics studies, wind effect on
buildings, aeroacoustic and other aerodynamic applications as shown in Fig. 3.3.
Although no longer in service, as an introductory remark it is interesting to briefly
describe this typical very large facility inaugurated in 1935 on the site of ChalaisMeudon and originally designed for full scale aircraft testing. Figure 3.4 shows an
aerial view of the wind tunnel. Of the Eiffel type, this wind tunnel has a contraction
ratio of 3.5 with an inlet of 100 m
2 at the beginning of the working section. The
collector captures the air from outside the facility through a large plenum which is
then accelerated to a maximum speed of 45 m/s. The exit of the open jet test section
has an elliptical shape with a 16 m major axis and an 8 m minor axis. Its diffuser
consists of a truncated cone-shaped tube with a length of 38 m, made of 70 mm thick
reinforced concrete. Downstream of the diffuser, the suction chamber is equipped
© Springer Nature Switzerland AG 2020
B. Chanetz et al., Experimental Aerodynamics,
Springer Tracts in Mechanical Engineering,
https://doi.org/10.1007/978-3-030-35562-3_3
51