Ultrasound-modulated two-fluid atomization of dilute polymer solutions

New findings presented can further our understanding of the atomization of dilute polymer solutions. First, contrary to the conventional view that vis coelastic liquids are more difficult to atomize than Newtonian liquids, it was found that aerodynamic conditions required to form uniform drops are le ss severe for some viscoelastic liquids than for Newtonian liquids. Under s imilar aerodynamic conditions, using ultrasound-modulated two-fluid atomiza tion at 54 kUz, 40-mu m-dia. uniform drops determined by the third harmonic frequency were obtained for gel-forming xantham grim solutions, but not fo r Newtonian liquids. Second, ultrasonic atomization yielded 350 - 400-mu m- dia. drops for aqueous solutions of rodlike polyethylene oxides (PEO) with molecular weights of 1-2 x 10(5) at 54 kHz, supporting previous predictions that PEO relaxation times may be as short as 10(-4) s. Third, at smaller m olecular weights (up to 2X 10(4)) , aqueous solutions of PEO behave like Ne wtonian liquids in accordance with modified Taylor's dispersion relation.