Simulations of microfluidic droplet formation using the two-phase level set method

A numerical study on the dynamics of droplet formation in a microfluidic double T-junction

“…It has been reported that 3D effects become less important as the channel aspect ratio (h/W c ) decreases below 0.05. 21 Usefulness of 2D simulation for studying droplet formation in T-junction has also been discussed by Li et al, 33 Liu and Zhang, 34 Leshansky and Pismen, 35 Amaya-Bower and Lee, 36 and Arias et al 37 In order to further validate the present numerical model, our numerical results are compared with experimental observation by Zheng et al 13 Figure 3 illustrates the four regimes of droplet formations in a MFDTD. In this figure, the water fraction wf denotes the ratio between the combined flow rate of aqueous flows (water) and the total flow rate of the carrier fluid (oil) and the aqueous flows.…”

“…In order to verify the formulation and computational implementation used in the present study, our result on the microfluidic T-junction is compared with that of Bashir et al, 21 which is based on three-dimensional (3D) finite-element formulation with the level-set method for tracking the moving interface. As shown in Fig.…”

“…This law matches with the droplet formation process in general droplet-based microfluidic devices, where the droplet size decreases as capillary number increases, while the frequency of droplet generation increases proportionally. [20][21][22]24 It also means that the alternating state depends significantly upon the capillary number. In all cases, the equilibrium point of wave functions corresponding to Dp ¼ À0.62, 0.23, and 0.32, which has a small deviation from zero.…”

“…The dynamics of droplet when it collides to the wall and breakup into two smaller droplets in a microfluidic symmetric T-junction was studied numerically using phase-field model. Three distinct regimes of droplet formation, namely, squeezing, dripping, and jetting, in microfluidic T-shaped junction were proposed by Menech et al 19,20 On the other hand, two phase level-set method used to investigate extensively wetting effects on the droplet size and droplet generation in a specific T-junction with different flow rate ratios, viscous ratios, and surface tensions were reported by Bashir et al 21 Three flow regimes depending on the capillary number and the flow rate ratio were also observed in a flow focusing device which was investigated by numerical approach. 22 Moreover, droplet generation in flow-focusing devices of various designs was studied by several research groups with the Lattice Boltzmann method.…”

Hydrophilic Surface Modification of PDMS Microchannel for O/W and W/O/W Emulsions

“…Due to the large surface to volume ratio characteristic of microfluidic devices, the channel surface properties play a vital role in a wide range of applications [15,16]. For droplet-based microfluidics, the wettability of the channel walls determine the type of emulsion that can be obtained: W/O emulsions are obtained in hydrophobic microchannels, while hydrophilic walls produce O/W dispersions.…”