Low Speed Wind Tunnels
3-Meter Diameter Wind Tunnel L-1A
The VKI low speed wind tunnel L-1A has a free jet test section of 3 m diameter and 4.5 m length. The 4.2 m diameter contrarotating fans of this facility are driven by a variable speed DC motor of 580 kW, allowing a continuous variation of velocity from 2 to 60 m/s. The contraction ratio is 4 with a typical turbulence level of 0.3 %.
The wind tunnel was designed as an aeronautical wind tunnel and used for testing aircraft models with spans up to about 2 m and 2-D wings at Reynolds numbers up to 4 x 106/m.
The tunnel is provided with a full range of test equipment, probes and models. A number of multi-component strain gauge balances, instrumentation for the measurement and recording of pressure and flow characteristics, including three-dimensional velocity measurements in wakes, and flow visualization methods are available for the needs of special applications such as, aircraft wakes, full-scale car components, wind turbines, solar protection systems, street lamps, ....
The open-jet test section can be fitted with a ground floor made of a flat plate located 0.5 m higher than the bottom part of the jet. This flat plate is equipped with an insert mounted on a strain gauge balance for drag measurements and with means for atmospheric wind simulation. It is used for tests on racing cyclists, on road vehicle models, on ground structures, ...
The open-jet test section may also be equipped with a rectangular 1.3 m x 2.36 m test section insert with solid side walls, which is used for tests of 2-D wings or structures, or aircraft, re-entry capsule or missile models. This insert is equipped with a transversal model support with strain gauge balances for the measurement of lift, drag and pitching moment. The model can also be oscillated in pitch, from -30 to +30 degrees, at frequencies up to 5 Hz, for dynamic stability studies.