Analysis of the Air Flow Generated by an Air-Assisted Sprayer Equipped with Two Axial Fans Using a 3D Sonic Anemometer

Abstract

The flow of air generated by a new design of air assisted sprayer equipped with two axial fans of reversed rotation was analyzed. For this goal, a 3D sonic anemometer has been used (accuracy: 1.5%; measurement range: 0 to 45 m/s). The study was divided into a static test and a dynamic test. During the static test, the air velocity in the working vicinity of the sprayer was measured considering the following machine configurations: (1) one activated fan regulated at three air flows (machine working as a traditional sprayer); (2) two activated fans regulated at three air flows for each fan. In the static test 72 measurement points were considered. The location of the measurement points was as follow: left and right sides of the sprayer; three sections of measurement (A, B and C); three measurement distances from the shaft of the machine (1.5 m, 2.5 m and 3.5 m); and four measurement heights (1 m, 2 m, 3 m and 4 m). The static test results have shown significant differences in the module and the vertical angle of the air velocity vector in function of the regulations of the sprayer. In the dynamic test, the air velocity was measured at 2.5 m from the axis of the sprayer considering four measurement heights (1 m, 2 m, 3 m and 4 m). In this test, the sprayer regulations were: one or two activated fans; one air flow for each fan; forward speed of 2.8 km/h. The use of one fan (back) or two fans (back and front) produced significant differences on the duration of the presence of wind in the measurement point and on the direction of the air velocity vector. The module of the air velocity vector was not affected by the number of activated fans.

Phase Doppler quantification of agricultural spray compared with traditional sampling materials

“…The majority of orchard sprayers in New Zealand are towbehind varieties with an anti-clockwise rotation causing the air to be lifted on the right side of the sprayer and dumped on the left. This approach leads to droplet interaction and inconsistences in the vertical profile (Manktelow & May 2011;García-Ramos et al 2012). For example, Khot et al (2012a) observed that flux profiles at distances of 3.0 to 4.5 m on the right side of the sprayer (with nozzles and air flow at 100% open) were 49% higher than on the left side.…”

Applicability of a 3D Laser Scanner for Characterizing the Spray Distribution Pattern of an Air-Assisted Sprayer

“…The distribution of the spray in the vicinity of the sprayer is often estimated by measuring the air flow generated by the fans. In this sense, the air flow generated by the sprayer can be characterized using high-precision anemometers such as sonic anemometers (two-dimensional or three-dimensional) which are used to measure the velocity components for different heights, sections, and distances from the sprayer [11,12].…”

A Remotely Deployable Wind Sonic Anemometer

“…This four-transducer orthogonal design, proposed in [4], is recognized as 2D ultrasonic anemometer. A 3D ultrasonic anemometer in [5] provides less aerodynamic turbulence by having complex design and mathematical equations. However, the design and implementation of ultrasonic anemometer mentioned is still very expensive.…”