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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Aerial Application Technology Research » Research » Publications at this Location » Publication #396774
Research Project: Improved Aerial Application Technologies for Precise and Effective Delivery of Crop Production Products

Location: Aerial Application Technology Research

Title: A model to predict chargeability of aerial electrostatic spray nozzles for fixed-wing agricultural aircraft

Author
item Martin, Daniel
item Fritz, Bradley
item Latheef, Mohamed

Submitted to: Journal of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Aerial electrostatic nozzles have been commercially used for the last 20 years to increase deposition and efficacy of agricultural sprays but little guidance is available to aerial applicators on how to achieve maximum benefits from this technology. Wind tunnel studies were conducted to determine the effect of airspeed and spray pressure for several commonly used aerial nozzles on spray chargeability. This data was used to create a user-friendly model which elucidates the effect of operational parameters for obtaining maximum spray charge. This model can help aerial applicators properly setup their electrostatic nozzles for optimal performance and to assure maximum environmental sensitivity.

Technical Abstract: Optimizing electrostatically charged aerial sprays of pest control products on field crops by fixed-wing aircraft is required to incur beneficial advantages such as improved deposits, increased plant canopy penetration and wrap-around effect associated with this technology. A spray mixture of tap water and a non-ionic surfactant was atomized through four electrostatic nozzles, TXVS-2, TXVK-3, 4, 6 at seven sets of airspeed and nozzle spray pressure combinations in a high-speed wind tunnel to determine spray chargeability. Using the parameter estimates (airspeed, nozzle orifice, liquid spray pressure, spray droplet spectra and flow rate), a response surface model was developed and incorporated into a Microsoft Excel-based app which can be installed and run on a smartphone. The goodness-of-fit of the model showed that the R2 values of spray droplet spectra used to build the model ranged from 0.941 to 0.985 which indicates that the measured values closely approximated the modeled values. This model is intended to help aerial applicators maximize the spray charge for specific nozzle and operational parameters and to conform with label requirements specified for application of crop protection chemicals. This would help ensure efficacy and mitigate off-target movement of crop protection products.