Low Speed Wind Tunnels
2x3 Meter Wind Engineering Facility L-1B
The VKI Wind Engineering facility L-1B consists of a specially designed test section interchangeable with that of the low speed wind tunnel L-1A and hence using the same return circuit, motor and power supply. The rectangular test section of L-1B is 2 m high, 3 m wide and 20 m long with a roughened floor to allow the growth of a turbulent boundary layer similar in nature to the lower part of the atmospheric neutral boundary layer.
Special care is taken in the proper simulation of turbulence parameters, namely intensity of fluctuation and power spectra. Optimal similarity conditions are obtained in the scale range 1/250 to 1/350. The test section ceiling is flexible and continuously adjustable to achieve control of the longitudinal pressure gradient. Flow velocity can be varied between 2 and 50 m/s making it one of the most powerful facilities of this type as far as Reynolds number simulation is concerned.
A special test chamber is provided at the beginning of the section for investigation of surface vehicle or boat aerodynamics, and is equipped with a six-component floor balance and facilities for boundary layer suction.
At the end of the section a 2.6 m diameter turntable is provided for investigation of building aerodynamics as a function of wind direction. The turntable is suitable for sand erosion testing and can be fitted with hot sphere probes to evaluate pedestrian wind comfort near high-rise buildings, and to study wind resource for turbine siting and the wake effect in and outside wind turbine parks. Wind loading on buildings and structures is evaluated using pressure taps and can include aeroelasticity on section model tests of suspension bridges. Concentration probes can be installed for investigation of pollutant dispersion in urban environments.