Recipient Organization
APPLICATION INSIGHT, LLC
2519 WILSON AVE
LANSING,MI 489062737
Performing Department
(N/A)
Non Technical Summary
There is an intense need for aerial spray application nozzles that are able to produce quality spray coverage while minimizing losses to spray drift. Aerial nozzles that are used for application of crop protection materials to the ground are usually chosen for their ability to produce coarser droplets with the smallest possible volume fraction of droplets below 150 microns. This is often called the "driftable fraction". Since most nozzles were originally designed for use in low-speed, terrestrial based applications, their external design and how it interacts aerodynamically with air flowing around it was generally irrelevant or even optimized for use with no or low speed flowing over it. In aerial spray applications, especially at high speeds, the aerodynamic conditions around the nozzles represent much higher forces, and as such can significantly impact the performance of the nozzles. Surprisingly, to date there has been no effort to redesign and optimize these nozzles to streamline and optimize the flow of air over their exterior surfaces. It is a well-known phenomena that any fluid (air being a fluid) passing over a sharp edge or transition will create turbulent eddies on the lee side of the edge. At high enough velocities, such as those found in aerial spray application, the energy contained in these eddies can be of enough magnitude to contribute to irregular droplet formation in the spray jet, leading to an increase in driftable fraction.Phase I of this project will use Computational Flow Dynamics software in conjunction with principles of aerodynamic flow to modify the exterior surfaces of existing straight stream and flat fan nozzle designs and the hardware designed to hold them. It will then show in high speed wind tunnel air conditions, such as those experienced during spray application, that the driftable fraction can indeed be reduced by incorporating designs that smoothly meld the transitions between surfaces and carefully managing the airflow as it interacts with the spray jet. In Phase II, this will be refined further in a wider range of operational conditions, again using Computational Fluid Dynamics (CFD) software to simulate and optimize the designs before final in-situ aerial testing and creation of the final product. The ultimate product of this project will be a nozzle system that improves aerial applicators' ability to manage drift risk in aerial applications, with lower drift in a broader range of weather conditions, while still maintaining an efficacious spray droplet spectrum.
Animal Health Component
50%
Research Effort Categories
Basic
(N/A)
Applied
50%
Developmental
50%
Goals / Objectives
The ultimate vision of this project is to improve the safety and effectiveness of aerial spray applications for safer, more sustainable food and fiber production. We will achieve this by improving aerial applicators' ability to make accurate, lower drift sprays. Reducing spray drift from aerial applications by the technology in this project will significantly increase the precision, efficiency and profitability of aerial applicators, reduce operational and environmental risks, and increase the number of acres that can be safely sprayed by efficient and productive aerial application. The project will achieve its objective through improving the nozzles used to apply the sprays: specifically, development of an aerodynamically optimized nozzle system designed for use with existing fixed or rotary-wing aircraft. Aerodynamically optimized nozzles, when used in high-speed application conditions, can meaningfully reduce the formation of small droplets that would be prone to drift while improving an operator's ability to lay a precision spray swath in a wider range of conditions. The system will give an applicator superior control over droplet size and swath placement by optimizing the turbulent interactions between the air in the slipstream and the spray jet. This will decrease the span of the droplet spectra produced by the nozzle, creating a more precise and controllable range of spray droplets. This system will find applicability in grains applications, specialty crops, nursery, and mosquito larviciding. These improvements will add tens of millions of dollars of productivity for applicators and increase our collective national health and safety by improving the proper placement of aerially-applied agricultural crop protection materials.
Project Methods
To make aerial spray application safer and more effective, our overarching goal in this project is to create nozzles that make a more effective droplet size distribution (DSD) in aerial applications. This means a significantly reduced volume fraction of driftable fine droplets, and, ideally, reduced volumetric median diameter would be produced to maintain label recommendations while minimizing the quantity of excessively large and wasteful droplets. More simply put, we would create fewer large and small droplets. This could also be expressed as reducing the statistical span ((DV10-DV90)/DV50) of the droplet spectrum, which would indicate a more uniform DSD.To achieve this, we've defined two Technical Objectives for the Phase I project. Our first objective is to design a set of nozzles that maintain the basic bench function of their conventional counterparts, ie: flow rate and spray pattern under static conditions at pressures typical to the majority of aerial application systems (30-60 PSI). The difference will be that the prototype nozzles will have surface geometry enhancements to improve their operation in high speed air (Stokes, 1845) Anderson, 2007). The designs will be evaluated in a virtual CFD environment before manufacturing to fine-tune the design. After manufacturing the nozzles, the second objective will be to fully evaluate each design in a real-world, high-speed wind tunnel. Objectives 1 and 2 may be somewhat circular because wind tunnel evaluation using Particle Image Velocimetry (PIV) will likely unlock deeper insight that will lead to a revisit of Objective 1 activities through several stages of refinement. As we noted earlier, the actual interactions involved are so complex that actual empirical testing is critical to the final result. This is likely to result in several final geometries optimized for various airspeed ranges.