COMPONENT ANALYSIS OF A WIND TUNNEL FOR PESTICIDE SPRAYING STUDIES

Abstract

Reducing drift is one of the key tasks when spraying pesticides in order to reduce negative environmental impacts. Drift studies are carried out in purpose-built wind tunnels, which have received considerable attention in their design and development. The aim of this work was to investigate the operating parameters of an electromagnetic water release valve (12w-160-15) used in a wind tunnel. The purpose of the valve is to release water from the water collection troughs. The valve was tested by supplying it with different voltages. The capacity of the valve with and without the outlet adaptor and with the improved outlet adaptor was also investigated. In addition, the possibility of controlling the valve's permeability and temperature using pulse width modulation was determined. The tests showed that the minimum voltage at which the outlet valve opens is 2.9 V. The 8 litres of water from the tray shall be discharged through the valve in 2 min 51 s without the adapter, in 2 min 55 s with the adapter and in 2 min 33 s with the adapter and the improved inlet adapter. The IPM control of the outlet valve is set to open at a fill factor of 29–26 and close at a fill factor of 3–4 at a frequency of 15–20 kHz respectively. The IPM modulation allows the valve to be supplied with a lower voltage and is less affected by temperature.