Drift Mitigation by Wingtip ModificationEPA Contract Number: 68D00231
Title: Drift Mitigation by Wingtip Modification
Investigators: Teske, Milton E.
Small Business: Continuum Dynamics Inc.
EPA Contact: Manager, SBIR Program
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $69,521
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text | Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Description:Drift of pesticides from the target site during aerial spray applications is a source of environmental concern due to its potential human health impacts, downwind contamination and damage to crops and livestock, and endangerment of ecological resources. With quantification of drift potential now possible with the computer model AgDRIFT (developed through a Cooperative Research and Development Agreement between the U.S. Environmental Protection Agency's Office of Research and Development and the Spray Drift Task Force, an organization of 38 chemical companies manufacturing pesticides in the United States), drift mitigation appears possible only by a change in application practices, spray nozzle design, pesticide formulation, or airframe wake effects. Airframe modification is likely to be most effective at the wingtips, where the structure of the wake flow field is influenced most easily. Previously published results (from the 1970s and early 1980s) suggest that off-target drift may be reduced considerably by the proper design of such wingtip-mounted devices, and that an improper design can actually increase drift. Unfortunately, the number of variables that influence the modified aircraft wake precludes the use of simple analytical models for the needed flow field investigation. The Phase I objective is to design several wingtip-mounted devices, using existing numerical tools (an aircraft fuselage/wake model and AgDRIFT) to optimize for drift mitigation, fabricate the final designs, and visualize their wake efforts in a wind tunnel experiment. If proven, these wingtip modifications could reduce considerably the buffer zones around sensitive areas in the United States and Canada, and expand the usefulness of available pesticides in a more accurate and environmentally safe manner.
This Phase I project will provide a solution to the wake flow field behind these devices, optimize their design for one commonly used agricultural aircraft, fabricate the devices, and visualize their wakes in a wind tunnel experiment. Phase II will field test the devices, quantifying the level of possible drift mitigation. The validated technology would then be made available to the retrofit market.
It is estimated that wingtip devices may be marketed for between $8,000 to $12,000 per aircraft. With an existing base of 4,000 aircraft in the United States and the anticipation that such approved devices will penetrate the market completely, the retrofit potential could reach $40 million.