Effects of elasticity on the spraying of a non-Newtonian fluid

The effects of elasticity on spray performance are investigated. In particular, the breakup of liquid filaments exiting the nozzle and the drop size distribution are investigated for a series of low-viscosity polyethylene oxide (PEO) elastic liquids sprayed through a commercially available spray nozzle. Multiple vertical and horizontal positions within the spray are studied. We find that the increase in the elasticity of the moderate to high molecular weight polymer PEO solutions substantially impacts the breakup of liquids exiting the nozzle, reducing the spray angle and the overall coverage of the spray. The vertical distance from the nozzle for the fluid to break up increases with an increase in extensional viscosity. The fluid extensional properties lead to liquid filaments between drops in the non-Newtonian fluids, and these lead to an increase in the average drop size within the spray and also suppress the formation of undesirable fine spray drops.