AT-11 is a closed loop wind tunnel with a single return duct and an open test section. The construction of AT-11 was completed in December 1988.

AT-11 specifications

  • Nozzle diameter – 2 250 mm.
  • Length of the test section – 4 000 mm.
  • Rate of rotation of the fan – 800 rpm.
  • Maximum flow velocity – 75 m/s.
  • Reynolds number in terms of diameter – 107.
  • Reynolds number in terms of length – 1.88 х 107.

(Рабочая часть – test section; диффузор – diffuser; сопло – nozzle; обратный канал – return duct)

Flow section of AT-11 is shown horizontally and consists of such key components as test section, diffuser, transition piece, single-stage axial flow fan, corner sections, guide vanes in corner sections, return duct, rapid flow extension area, settling chamber with honeycomb, contractor (nozzle). Load-bearing structure of AT-11 wind tunnel consists of transverse frames and stingers and is made out of wooden parts. Both internal and external surfaces of the tunnel are made out of 5 mm thick plywood. There is no filling between the two layers of plywood. Test section of AT-11 wind tunnel is open. Its length (Lts) from the nozzle exit area (nozzle diameter Dn is 2250 mm) to the diffuser entry is 4000 mm. Flow in the test section is an area of free turbulent air flow. In order to place models and measurement equipment in the test section two coordinate positioning devices that slide into test section using guide rails are used.