Causal mechanisms of drop breakup in turbulent flows

The fragmentation of drops and bubbles in turbulence determines the rate of many processes in engineering and environmental fluid flows. The nonlinear coupling between interfacial and hydrodynamic stresses poses a fundamental difficulty to model reduction, which we here address by decomposing the flow into outer and inner fields. We show that the outer field is independent of the drop dynamics and drives deformation, whereas the inner field responds to the deformation by dissipating the interfacial energy through the genesis of turbulent eddies. Drawing from these observations, we derive a simple analytical model that reproduces the breakup statistics obtained from ensembles of direct numerical simulations of drops and bubbles. Our results reveal a causal link between the intermittency of turbulent flows and the memoryless breakup statistics.