22 August 1997

New wind tunnel is a big step forward

By Geoff Ashcroft

JUST how does a particular nozzle perform with a specific chemical type – and in a range of different wind speeds, and on a variety of different crops?

These are questions which may now be answered more completely, following the inauguration of a new wind tunnel facility at Silsoe Research Institute.

The £500,000 wind tunnel has been designed to provide realistic spraying conditions – chemical can be applied to crops grown in trays which fit into the tunnels adjustable floor system.

"Its quite a breakthrough in our research facility," explains Professor Paul Miller, Silsoes head of chemical applications. "Using our previous test facility, we were unable to spray any pesticides and carry out such realistic tests."

Being able to apply active pesticide in a wind tunnel for the first time puts the institute in a favourable position – it is believed to be one of only three such installations in the world offering this capability.

The "working" section of the wind tunnel measures 7m (23ft) long, 3m (10ft) wide and 2m (6.5ft) high and offers a wind speed range from 0.5 to 10m/sec allowing researchers to simulate a wide range of conditions – from a light breeze to a tree felling gale.

Full-scale trials

It also means full-scale trials can be carried out using nozzle systems or sections of a spray boom, working on any crop, at any growth stage.

Once a test cycle is completed, the wind tunnels own automatic cleaning system is brought into action, rinsing the internal surfaces of the stainless steel wind tunnel, in readiness for the next test.

Silsoes Prof Paul Miller and his new wind tunnel. "Break-

through in research,"

he says.

Wind tunnel in action …the result

of using different nozzle types at different wind speeds can be recorded.