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is 1, the Reynolds number based on the model chord length 0.25 m is
120 × 10 6 , twice as high as the Reynolds number of cruise flight B747.
Another example is the European Transonic Wind Tunnel ETW, scheduled for completion in 1993. The test section is 2.4 m × 2.0 m, with a
minimum operating temperature of 90 K and a maximum experimental
Reynolds number of 5 × 10 7 .
(1) National transonic wind tunnel, Langley experimental center, NASA
The National Transonic Facility (NTF), NASA Langley Laboratory,
USA, is a single-loop, continuous, low-temperature pressurized wind
tunnel driven by an axial flow compressor (or axial flow fan, axial
fan), built in 1983 (as shown in Figs. 6.46, 6.47, 6.48, 6.49, 6.50 and
6.51). The wind tunnel test section parameters such as total temperature, total pressure, and fan speed can be independently controlled, so
as to, respectively, study Ma number (compression), the Re number
Fig. 6.46 Outdoor scene of NTF
Fig. 6.47 US national continuous transonic low-temperature pressurized wind tunnel