DROP SIZE SCALING ANALYSIS OF NON-NEWTONIAN FLUIDS

Current spray materials utilized by the U.S. Department of Agriculture (USDA) Forest Service are non-Newtonian in nature; a better understanding of their atomization behavior will improve their efficiency, efficacy, and total accountancy and environmental fate. To this end, this study first reviews the state of Newtonian and non-Newtonian spray material characteristics, and attempts data compression with available wind tunnel data. Using first principles of dimensional analysis, consistent nondimensional parameters are developed and grouped into well-accepted numbers, such as the Reynolds and Weber numbers. The water atomization data from the USDA Forest Service drop size distribution database are then correlated with simple expressions that recover data trends. We propose a form of the non-Newtonian terms for the atomization of viscoelastic fluids, and suggest that a systematic laboratory benchtop examination of applicable non-Newtonian materials be undertaken to test the validity of the proposed relationships.