Windtunnel
|
Purposes The windtunnel at Vrins Luchtonderzoek is a closed circuit, |
 |
- calibration of anemometers and dust samplers
- assessment and comparison of the sampling characteristics of dust samplers
- assessment of the aerodynamic properties of dust particles
- evaluation of wind erosion reduction measures such as crustforming agents.
up
Specifications
It is possible to generate wind speeds up to 15 m/s in both directions.
The wind tunnel is easily accessible from all sides to mount and adjust
instruments. The wind tunnel is extraordinary because of its length, which
is 10 m. The cross section of the lower test section is 0.75 m. The upper
section has a width of 0.9 m. and a height of 1.8 m. Several instruments
are available to measure wind speed and to visualize the flow patterns.
It is also possible to mount a dust filter to remove dust and particles
form the air flow and to remove turbulent eddies and other non-uniform
flow patterns.
up
Experiments
A number of experiments has been carried out to investigate the behaviour
of the flow in the wind tunnel. Two major types of experiments have been
done:
- Visualising the flow patterns
- Measurement of wind speed profiles using pitot-static tubes
From these experiments the following conclusions can be drawn:
- The presence of the dust filter suppresses turbulence shortly after
the flow has passed the filter.
- When the flow passes the test section before it passes the filter, the
filter has low influence on the flow pattern and a well-developed turbulence
seems to be present.
- Without the dust filter large in-homogeneities exist that result spatial
differences in wind speed up to +/- 25 %.
up
An extensive report about the performance of the wind tunnel is available
in Dutch.
up