The horizontal aeolian wind tunnel is a 15 m long open circuit, suction type tunnel and the test section is 0.60m wide and 0.90m high. A small bell-mouth, with a screen attach to it, is placed at the inlet in order to reduce the effect from low frequency fluctuations distorting the natural turbulence characteristics of the internal boundary-layer.
A sand feed mechanism follows one meter downwind of the inlet to maintain a constant transport rate downwind under the influence of a pre-designed boundary layer. Sand transported in the HW is trapped in a sand collector in the downwind end of the tunnel, just in front of the fan and motor.
The working area is the section from 10-13 m downstream of the entry. The side panels of the tunnel body consists of a set of gates (windows) that can swing up thus permitting access to the interior. Another set of gates in the ceiling of the tunnel above the working section offer an alternative access to the working section. The latter set of gates is primarily used to install instruments which must be operated partly from the outside or connected to an external power supply or recording system.