A criterion for when an emulsion drop undergoing turbulent deformation has reached a critically deformed state

Turbulent breakup in emulsification devices is a dynamic process. Small viscous drops undergo sequence of oscillations before entering the monotonic deformation phase leading to breakup. The turbulence-interface interactions prior reaching critical are therefore essential for understanding and modeling This contribution uses numerical experiments characterize critically deformed state (defined as from which will follow deterministically, even if no further external stresses would act on drop). Critical does not coincide with threshold maximum surface area, previously suggested. A drop when neck has formed locally curvature such that Laplace pressure exceeds smallest bulbs connected by neck. corresponds destabilizing internal flow, thinning Assuming leads two spherical linked cylindrical neck, achieved diameter becomes smaller than radius bulb. role emulsifiers also discussed.