Nozzle Injection Characteristics of Visco-Elastic Fluids

Injection flow characteristics of visco-elastic fluids from a nozzle into air have been investigated. As viscoelastic fluids, the dilute solutions of polyethylene oxide, of hydroxypropylcellulose and of polyacrylic acid were used. The injection filaments formed in the downstream of primary droplet from a nozzle with the diameter of 0.5 mm injected by a piezoelectric element were observed by a high-speed video camera. Injection velocity was changed from 0.32 to 4.76 m/s, where the apparent extensional rate ranged from 276 to 5,270. From the results, it was found that each filament length of each fluid increases monotonically as a function of the capillary, Ohnesorge and Weissenberg numbers and all data can be plotted in one curve independently of materials.