Numerical simulation of droplet deformation and breakup in shear flow
Based on lattice Boltzmann color gradient model,numerical simulation was carried out for the deformation and breakup of droplets in two-dimensional shear flow.Effect of capillary number Ca,Reynolds number Re and viscosity ratio λ of different fluids on droplet deformation in shear flow was investigated.Three different deformation or breakup ways of droplets were distinguished in the phase diagram of Re-Ca.In addition,to understand the effect of interface on the fluid inside the droplet,tracer particles were introduced,and their motion patterns in the droplets were analyzed.Results show that the increase of Ca number resulted in enhanced deformation effect and weaker deflection angle of droplets,which affected the motion of tracer particles greatly.With the increase of Re number,the droplets deformation became strong,while weak deflection angle was observed.These phenomena affected the motion of tracer particles significantly.When the viscosity ratio was low(λ＜0.8),the droplets underwent a large deformation process.When the viscosity ratio continued to increase,the deformation parameter decreased.The closer the tracer particle to the initial center of circle,the longer the movement distance,which caused greater shearing effect on tracer particles.They got closer to the interface and stabilized ultimately.
color gradient modelshear flowdroplet deformationdroplet breakuptracer particle
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