Technical gazette, Vol. 28 No. 5, 2021.
Preliminary communication
https://doi.org/10.17559/TV-20200428144856
Mathematical Method for Droplet Size Distribution of Agricultural Nozzles
Kurt Tomantschger
; University of technology Graz, Faculty of Mathematics, Physics and Geodesy, Steyrergasse 30, 8010 Graz, Austria
Dragan V. Petrović
; University of Belgrade, Faculty of Agriculture, Nemanjina 6, 11 081 Belgrade - Zemun, Serbia
Rade L. Radojević
; University of Belgrade, Faculty of Agriculture, Nemanjina 6, 11 081 Belgrade - Zemun, Serbia
Vjekoslav Tadić*
orcid.org/0000-0002-2307-9255
; University of J. J. Strossmayer in Osijek, Faculty of Agrobiotehnical Sciences Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia
Abstract
One of the technical factors from agricultural nozzles and overall plant protection is droplet diameter, which exclusively depends on working pressure, ISO number and nozzle type. Therefore, this paper was aimed to describe mathematical model for droplet size distribution. Through field exploitation experiment, data was used from three ISO numbers of nozzles (hollow cone 80 015; 02 and 03), two air-assisted sprayers (axial and radial fan) and two permanent crops (vineyard and an apple orchard). Water sensitive papers were used for evaluation of droplet diameters, and digital image analysis with Image J software was used for data processing. Mathematical model through homogenous diffusion equation and simplified differential equation shows that droplet size distribution had exponential function of modelling. Theoretical mathematical model was confirmed in experimental results, where coefficient of determination of exponential regression model for 80 015 nozzles was 0.93 with 5.15 of RMSE. The same coefficient for 80 02 nozzles was 0.96 with 2.88 of RMSE and for 80 03 nozzle R2 was 0.93 with 3.25 of RMSE. In addition, it is proved that droplet diameter depends on operating pressure with very high negative correlation (80 03 nozzles: r = −0.98; 80 02 nozzles: r = −0.97; 80 015 nozzles: r = −0.95). This data will help future researchers in their papers to facilitate and describe similar models for plat protection processes, and all agricultural producers to determine optimal operating pressure which is immensely important in economic, biologic, technical and ecologic aspect.
Keywords
agricultural nozzles; diffusion equations, droplet size distribution; partial differential equation; plant protection
Hrčak ID:
261355
URI
Publication date:
15.8.2021.
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