← Research · M.S. (R), IIT Delhi · 2018 – 2019
Droplet formation in microfluidic T-junctions
Physical Review Fluids · 2020How droplets form and how the flow regime changes in a T-shaped microfluidic device.
Key findings
- 3D multicomponent lattice Boltzmann model with a Carreau–Yasuda continuous phase, validated against T-junction experiments.
- Stronger shear thinning of the continuous phase gives larger droplets and changes their shape from spherical to plug-shaped, behaviour usually seen only at low capillary number in Newtonian flows.
- Mapped the transitions between parallel flow, droplets in the channel and droplets at the junction as a function of the Carreau and capillary numbers.
What I did
- Parallel (MPI) lattice Boltzmann solver written from scratch in C/C++.
- Validated against in-house experiments.
V. G. Agarwal, R. Singh, S. S. Bahga, A. Gupta, Physical Review Fluids 5, 044203 (2020).
Experiment vs. simulation
High-speed movies of the T-junction experiments next to the lattice Boltzmann simulations for the three droplet flow regimes.
Experiment frames mirrored and cropped to the junction so that both columns flow left to right. Simulations: Cr = 100, 10 and 0.01 (top to bottom) at Ca = 0.5, n = 0.5.
Effect of shear thinning
A lower power-law index n (stronger shear thinning of the continuous phase) gives larger droplets; Ca = 0.1, Cr = 1.