HAL Id: hal-02587578
https://hal.inrae.fr/hal-02587578
Submitted on 15 May 2020
HAL is a multi-disciplinary open access
archive for the deposit and dissemination of
sci-entific research documents, whether they are
pub-lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.
Spray-drift from an axial fan sprayer Full-scale
measurement in a wind-tunnel: low-drift’ v’s standard
nozzle performance
G.M. Richardson, Alexandra Herbst, P. Roux, Pierre Delpech
To cite this version:
G.M. Richardson, Alexandra Herbst, P. Roux, Pierre Delpech. Spray-drift from an axial fan sprayer
Full-scale measurement in a wind-tunnel: low-drift’ v’s standard nozzle performance. 8th Workshop
on Spray Application Techniques in Fruit Growing, Jun 2005, Barcelona, Spain. pp.1, 2005.
�hal-02587578�
Spray-drift from an axial fan sprayer: Full-scale measurement
in a wind-tunnel: ‘low-drift’ v’s standard nozzle performance
Richardson, GM
1; Herbst, A
2; Roux, P
3and Delpech, P
4References
➤ P Balsari And P Marruco. Influence of canopy parameters on spray drift in vineyard Aspects of Applied Biology 71, 2004 pp 157-164.
➤ B Heijne, M Wenneker And J C Van De Zande. Air inclusion nozzles don’t reduce pollution of surface water during orchard spraying in the Netherlands Aspects of Applied Biology 66, 2002 pp 193-199.
1Silsoe Research Institute, Wrest Park, Silsoe, Bedford MK45 4HS, UK
2BBA, Fachgruppe Anwendungstechnik, Messeweg 11/12, D-38104 Braunsweig, Germany 3Cemagref, UMR ITAP, BP5095, 34033 Montpellier cedex 1, France
4CSTB, 11 rue Henri Picherit, BP 82341, 44323 Nantes cedex 3, France
Comparisons of airborne-drift measurements: Vertical distributions from Layer-1
Distributions of airborne-drift (z = 0.25 m) and Sedimentation: from LAY-1 to LAY-4 downwind (See Fig. 1)
Wind tunnel compared to Field distributions of Spray sedimentation ratios (‘low-drift’/standard nozzle). Each
normalised by Application volume rate.
Figure 1: Cross section view of the experimental arrangements in the wind tunnel
Z=7 m Z=7 m Z=575 cm Z=25 cm Z=5 m Wind inlet width 6 m -3 m 3 m +2 m -2 m X = 0 m 5 m 7 m
LAYER-1 LAYER-29 m LAYER-313 m LAYER-417 m
Turning vanes
Wind
12 collectors line spaced 50 cm
2 collectors line
Z=25 and 75 cm Z=75 cm
Z=25 cm
X
Z
(Relative ‘Drift Index’ values are given in boxes)
➤ A ‘No crop’ comparison over predicts the benefit of ‘low-drift’ nozzles
➤ Four rows of crop reduce the nozzle effect after spray filtering & redistribution
➤ Favourable evaporative conditions (>6ºC Wet Bulb Depression) yield little effect
➤ The Velocity measurements shows unabated wind beneath the artificial canopy
➤ The ratio of Airborne-drift to sedimentation shows a marked difference between nozzle types for ‘No crop’
➤ As expected from the vertical distribution, the effect of the crop is to reduce all drift values: by almost a decade
➤ The contrast in sedimentation between nozzle types is maintained: indicative of large ‘low-drift’ droplets falling beyond the crop
NB: Airborne measurements, when in a field context; need to be made above any filtering plants in the downwind zone.
➤ ‘Low-drift’ nozzles can produce a worse sedimentation within 5 m or so downwind of the last crop row; with axial-fan spraying
➤ Extrapolation of the full-scale Syrah Vineyard data of Balsari & Marruco suggests so (at both of their growth stages)
➤ And Heijne et al.’s June apple orchard data demonstrates the same with a cross-flow sprayer and two types of low-drift
nozzle 0.1 1.0 10.0 1 10 100 . No crop With crop With crop & (Delta T) GS (27) Syrah @ 1.8m GS(33) Syrah @ 1.8m Heijne et al 2002 TDM Heijne et al 2002 TDF
Distance from (a half row width downstream of outer-row) , (X - 0.5*W) (m) Sedimented Spray-drift Ratios (Each Normalised by its applic.n vol. rate
No crop target With four rows of artifical crop
0 1 2 3 4 5 6 0.1 1.0 10.0 100.0 -2 0 2 4 Standard 'Low-drift' UMean 1.00 0.36
Horizontal Velocity, U ms-1(+u rms bars)
Airborne drift flux (% of applicn vol. rate)
Height z, (m) 0 1 2 3 4 5 6 0.1 1.0 10.0 100.0 -2 0 2 4 Standard 'Low-drift' Standard 'Low-drift' UMean Horizontal Velocity, U ms-1(+u
rms bars)
Airborne drift flux (% of applicn vol. rate)
Height z, (m)
0.10;0.10
0.09;0.09
1.00; 1.00
0.97; 0.97
No crop target With four rows of artifical crop
0.1 1.0 10.0 100.0 1 10 100 0 2 4 6 1 10 100 Standard Airborne 'Low-drift' Airborne Standard Sedimentation 'Low-drift' Sedimentation UMean 0.1 1.0 100.0 1 10 100 0 2 4 6 1 10 100 Standard Airborne 'Low-drift' Airborne Standard Airborne 'Low-drift' Airborne Standard Sedimentation 'Low-drift' Sedimentation UMean
Adjusted distance downstream from sprayer, x-6 (m)
Airborne or sedimentation-drift (% of applic n vol. rate) Horizontal V elocity , U ms -1 (+u rms bars)
Adjusted distance downstream from sprayer, x-6 (m)
Airborne or sedimentation-drift (% of applic n vol. rate) Horizontal V elocity , U ms -1 (+u rms bars)
