Dawei Luo, chemical engineering, Texas A&M University, college station, TX 77840, Haejune Kim, Chemical Engineering Department, Texas A&M University, 200 Jack E Brown Building, Sollege Station, TX 77843, and Zhengdong Cheng, Texas A&M University, Chemical Engineering Department, College Station, TX 77843.
The formation of droplets resulting from breakup of aqueous thread into immiscible liquid in microfluidics device with flow focusing geometry at various conditions was investigated. The full transient from startup to breakup into droplets was simulated numerically by solving the time-dependent Navier-Stokes equations of two phase flow using volume-of-fluid (VOF) method and level set method. The numerical simulation results were compared with experimental data at different flow rates, and the mechanisms of droplets formation were discussed. Results showed that the numerical scheme developed was accurate and can be used to capture the dynamics of droplets formation at different flow conditions. Different factors, such as Reynolds number and Webbers number, influencing the dynamics of droplets breakup were also studied.