Correction and improvement of a widely used droplet–droplet collision outcome model

Abstract

The widely used droplet–droplet collision outcome model distinguishing stretching separation (SS) and fast coalescence (FC) (named SS/FC model) proposed by Jiang et al. [J. Fluid Mech. 234, 171 (1992)] is corrected and improved in this study. By re-deriving the momentum conservation, the correct mathematical expression of the tangential velocity along the sliding direction is obtained. Moreover, to reduce the uncertainties of model applications, the model is improved by expressing the constants as a function of the Ohnesorge number and droplet size ratio. The validation results demonstrate the effectiveness of the improved SS/FC model.