Computational study on the breakup of FENE-P drop migrating through microconfinement with gradual entry and exit.

In the present study, we deciphered the breakup dynamics of a viscoelastic Finitely Extensible Nonlinear Elastic – Peterlin (FENE-P) drop migrating through confinement with gradual entry. Drop breakup considerably depends upon the channel orientation and nature of drop entry inside the confinement. Our previous computational study reported the breakup phenomenon of FENE-P drop inside confinement with sudden entry. We observed that the critical capillary number for drop breakup in confinement with a gradual entry differs from that with sudden entry. Drop breakup was accessed at different Deborah numbers and viscosity ratios. The critical capillary number variation with Deborah number and viscosity ratio was also discerned in the study. Drop breakup with the formation of daughter and satellite drops was represented with a map showing drop interface position at different axial positions of the microchannel. The interface tracking for the viscoelastic drop was done using the Volume of Fluid (VOF) method, while the simulations were performed on open source solver Basilisk. FENE-P viscoelastic drop exhibits a shear-thinning behavior, and it can represent the flow of cells and drug carriers migrating in blood vessels. Thus the drop flow inside confinement can replicate the flow of anti-cancer drug carriers like hydrogel inside minute blood capillaries. Further, a drop breakup study will help get deeper insights into finding critical conditions for nano-carrier disintegration. The nano-carrier disintegration is required to achieve on-demand burst drug release at the cancer site.