Dripping and jetting of semi-dilute polymer solutions co-flowing in co-axial capillaries

This work is focused on the mechanisms of dripping and jetting flow modes viscoelastic semi-dilute polyacrylamide aqueous solutions co-flowing with silicone oil in co-axial capillaries. A phase diagram dripping, jetting, intermediate established. It was found that mode, elongation velocity filament between terminal droplet inner capillary controlled solely by continuous rate. At same time, decrease diameter due to both stretching outflow polymer solution into droplet. In thread evolve three stages. first stage, average jet increases, whereas second third stages, it becomes constant corresponds phase. The transition from stage defined appearance waves resulting formation beads-on-string structure. neighbor beads decreases exponentially governed relaxation which strongly depends concentration, but does not depend simple physical model proposed for describing evolution dimensions filaments during development instability. universal character sizes, independent concentration semi-diluted rates phase, revealed.