An exploratory study on fluid particles breakup rate models for the entire spectrum of turbulent energy

Journal article, 2018

In this study, the role of turbulence on the formulation of breakup kernels for fluid particles in dispersed multiphase flows is demonstrated. Two pieces of information for model derivations including the turbulent energy spectrum and the second-order structure function are chosen as the main candidates to extend the models for the entire turbulent spectrum, contrary to the original expressions that are limited for the inertial subrange. Further, a two-step validation procedure is proposed to incorporate the effect of turbulence for model validations, that is, the original and the extended models are compared and validated against two sets of experimental data for breakup rates. The first set covers the inertial subrange, while the second set is a dataset that includes direct measurements toward the dissipation subrange of turbulence. The results show that the predictive abilities of breakup kernels can be enhanced by the model extension, when the droplet diameters are outside the inertial subrange of turbulence. This work, thus, answers how the entire spectrum of turbulence can improve the breakup kernels and proposes a validation method to include the effect of turbulence for the validation of breakup kernels.