Large-scale dispersed phase-resolved direct numerical simulation (LDPR-DNS) of mechanically stirred reactors: Understanding the dispersion mechanism of multiphase flow and qualifying the droplets produced

Dispersed phases significantly strengthen the rate phenomena occurring among immiscible phases, which affects a reactor performance, but the understanding is limited. In this work, a Large-scale Dispersed phase Resolved Direct Numerical Simulation (LDPR-DNS) was established to directly capture the dispersed phase. Meanwhile, a water model was done based on the modified Froude number with a density correction and indicates LDPR-DNS is in high agreement with experimental observations. The typical transient transport phenomena of dispersed phases, including their generation, deformation and death, can be revealed by LDPR-DNS, and found that the formation of dispersed phase is the result of the inertial and viscous force to overcome the interfacial tension. Furthermore, a dimensionless number - Capillary number (Ca) - was introduced to quantitatively characterize the formation of dispersed phases. Finally, two new parameters, which describe the renewal rate of dispersed phase, were defined and the effect of impeller rotation speed was assessed.