Numerical Study on the Effect of Temperature on Droplet Formation inside the Microfluidic Chip

The flow-focusing method is a technology for microfluidic droplet control, and the temperature can effect on the droplet formation. In this study, the droplet formation in the flow-focusing method during the squeezing of dispersed phase by the continuous phase is simulated using CLSVOF, with the consideration of the effects of temperature on droplet size, shape and frequency. The simulation results are consistent with experimental data. The simulated results demonstrate that the droplet size increases with the increase of inlet phase temperature, while the shape regularity and forming frequency decrease, the maximum increase of droplet size is 16%, the biggest drop of droplets number is 29%, and the biggest drop of the roughness parameter is 5%. When the inlet temperatures of the continuous phase are not equal, dripping and jetting are observed in the flow regime of droplet dispersed phase. The mechanism of the temperature influence on droplet formation and the detailed process of droplet formation under different flow regimes are discussed. At the same time, the radial size of droplet breakup point under different flow regimes is compared. The simulation results provide insights in better selection of the control parameters for droplet formation technology.