Trisonic Wind Tunnel N-3

The unique trisonic N-3 blow-down wind tunnel has started operation in 1965. The use of a pressure ejector with partial air recirculation enabled operation in three speed regimes: 

  • subsonic, 
  • transonic,
  • supersonic (range of obtained Mach numbers Ma = 0.2–2.3). 

The tunnel is supplied from two spherical compressed air tanks with the combined volume of 2880 m3 and maximum pressure of 7 atm. The air is compressed by compressors with a total capacity of up to 2000 kW, appropriately purified and dried. 

The average operating time of the wind tunnel, is:

  • for supersonic Mach velocities about 3 minutes,
  • for transonic Mach velocities about 5 minutes,
  • for subsonic Mach numbers Ma = 0.3–0.5 up to several minutes.

Measurements are performed in a measuring chamber with the diagonal cross section of 0.6 x 0.6 m, which classifies the tunnel as the largest and fastest facility in Poland.



Dimensions of the measuring space – height x width

0.6 m x 0.6 m

Measuring space dimensions – length

1.5 m

Working medium


Speed of the working medium

Ma = 0.2–2.3

Wind tunnel N-3 – scope of services

  • pressure and weight tunnel tests of aircraft models, measurement of their aerodynamic characteristics and pressure distribution;
  • measurements of aerodynamic loads on elements of aircraft models, such as:
    • wings, 
    • horizontal and vertical stabilizers, 
    • control surfaces, 
    • stores, etc.;
  • measurements of the hinge moment on the controls;
  • buffeting boundary determination and its intensity in a wide range of flow velocities;
  • flow visualizations using the following methods:
    • imaging anemometry (Particle Image Velocimetry, PIV), 
    • oil,
    • Schlieren (monochrome and color);
  • tunnel tests of aerodynamic characteristics of profiles;
  • pressure measurements of transients with a system forcing oscillatory movements.