Simmons’ root-normal distribution

In the breakup regimes, a droplet may undergo secondary breakup when the breakup time is reached. The droplet size distribution after bag or multimode breakup may follow the Simmons root-normal distribution pattern 264 with MMD/SMD equal to 1.1,... 

Wu, Ruff and Faethl249 made an extensive review of previous theories and correlations for droplet size after primary breakup, and performed an experimental study of primary breakup in the nearnozzle region for various relative velocities and various liquid properties. Their experimental measurements revealed that the droplet size distribution after primary breakup and prior to any secondary breakup satisfies Simmons universal root-normal distribution 264]. In this distribution, a straight line can be generated by plotting (Z)/MMD)°5 vs. cumulative volume of droplets on a normal-probability scale, where MMD is the mass median diameter of droplets. The slope of the straight line is specified by the ratio... 

The initial and total breakup times also need to be determined, as well as fragment size distribution information. Unanswered questions include Does Simmons scaling rule (MMD/D32 1.2) hold for non-Newtonian drop secondary breakup and Will non-Newtonian drop secondary breakup produce a root-normal fragment size distribution ... 

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