Experimental and linear analysis for the instability of non‐Newtonian liquid jets issuing from a pressurized vibrating nozzle

Abstract

The laminar capillary breakup of viscoelastic jets to produce polymeric microcapsules is analyzed experimentally and theoretically. The phenomenon is based on subjecting a capillary jet to controlled disturbances so that it eventually breaks up forming individual droplets. A dispersion relation from a temporal linear analysis to describe and predict the system behavior that includes the Oldroyd-B constitutive equation to take into account the viscoelasticity of the liquid is obtained. Dispersion curves relating growth rate and wavenumber of the perturbed jets are compared with experimental conditions and the chosen mathematical approach is found that fairly describes the system. The obtained dispersion relation eases the study of the effect of viscosity, elasticity, through relaxation times, and flow rate in the system. The approach allows finding the best conditions to obtain homogeneous droplets and describes the system qualitatively.

Primary breakup of shear‐thickening suspension jet by an annular air jet

“…Researchers also studied the influence of the rheological and physical properties of working fluids, such as surface tension 37 and viscoelastic properties 38–41 . According to the research of Zhao et al, 42 the viscoelasticity of coal water slurry (CWS) affects the breakup morphology and breakup length.…”