Modeling the breakup of fluid particles in turbulent flows

A model for breakup of fluid particles in turbulent flows is presented in this article. In the new model two criteria, one stress and one energy criteria, are required to be fulfilled for breakup to occur. A new model for interaction frequency between fluid particles and turbulent eddies is also introduced. Analysis of the model reveals that eddies close in size and up to three times larger than the fluid particle contribute most to the overall breakup rate. This explains the experimental findings by the authors and by other researchers presented recently in the literature that fluid particles often deform significantly before breakup occurs. A high-speed imaging technique, 4000 Hz, was used to measure the breakup rate directly without introducing assumptions regarding the daughter size distributions and the number of fragments formed upon breakup. Validation with these measurements shows that the new model gives excellent predictions. 0 2006 American Institute of Chemical Engineers.