The cryogenic wind tunnel

Modeling and Wind Flow Analysis of an Eiffel (Open) Type Sub-Sonic Wind Tunnel

“…The use of a cryogenic tunnel is a third option. The National Transonic Facility (NW), which NASA built at its Langley Research Center in the beginning of 1971 [36], was the first of its kind. The same concept applies to a low-speed tunnel, even though this tunnel is designed for transonic experiments.…”

“…KKK (Kryo-Kanai K61n): This large cryogenic wind tunnel was built at DLR Cologne as a conversion of a traditional closed-circuit fan-driven atmospheric pressure tunnel. [36] ii. Vertical Short Take-off and Landing V/STOL Wind Tunnels Because of the large downwash angles generated by powered lift systems in the transition flight region, these tunnels require a much larger test section for a given size model.…”

Temperature control of cryogenic wind tunnel with a modified L1 adaptive output feedback control

“…The cryogenic wind tunnel is a ground test facility which can produce flight Reynolds number by operating wind tunnel in cryogenic temperature with injection of liquid nitrogen. 1 In cryogenic wind tunnel, the Reynolds number is increased due to the increased gas density and decreased viscosity of the gas, and nitrogen behaves as a perfect gas at cryogenic temperatures. 2 At present, some cryogenic wind tunnels with high Reynolds number capabilities have been built in some well-known research institutes in the world, such as the DNW-KKK cryogenic wind tunnel in Ko¨ln, Germany; 0.3 m Transonic Cryogenic Tunnel (TCT) and the National Transonic Facility (NTF) at NASA in the United States; and the European Transonic Wind (ETW) tunnel in Germany.…”