Study of Dynamic Break-Up of Capillary Jet Using Level-Set Method

摘要

Capillary jets, created due of interfacial instability in two-fluid system under the effect of surface tension, are widely encountered in nature. In the present work, dynamic breakup of a axisymmetric liquid jet injected vertically into another immiscible liquid is investigated numerically at various injection velocity, for four different disperse fluids with water as continuous fluid. For this purpose, an in house Level Set (LS) methodology based code is used. The two fluid flow simulation methodology uses finite volume method for solution of Navier-Stokes and finite difference method for solution of LS equations. An excellent agreement is found between the present simulation and a published theoretical and experimental work for detached bubble diameter. Furthermore, different breakup modes reported in the published experimental results are captured in the present simulations. The results show a greater sensitivity of jet length and drop diameter to the Reynolds number. However, viscosity ratio has negligible effects on breakup dynamics. The results shows that the transition from dripping mode to jetting mode takes place at Weber number 2.2.