ID 297

Numerical investigation of the effect of density ratio on secondary breakup

 

Abstract:

Secondary atomization has been the subject of interest for the last few decades. Further breakup of droplets is a phenomenon manifested in both natural as well as industrial environments. While there have been several experimental studies at ambient conditions which involve typical density ratios ( R = ρliq / ρgas > 500 ), most of the numerical investigations have been at much lower density ratios ( R < 50 ). The current work is carried out to bridge this gap and by evaluating the single drop breakup behaviour for a wide range of density ratios (10-1000). It is well known that the non-dimensional parameter, aerodynamic Weber number (We) dictates the regimes of secondary breakup. Therefore, both R and We are varied to conduct fully resolved Volume-of-Fluid (VOF) simulations and capture the different regimes of single droplet breakup at different density ratios. The drop deformation dynamics and subsequent breakup phenomena are investigated in detail. A phase plot against R-We is presented that represents the variation in the drop breakup dynamics at various Weber numbers and density ratios. It is observed that the breakup dynamics exhibit significant differences at low density ratios. The droplet motion and temporal characteristics of its deformation are also presented.