Slow Formation at Nozzles

The slow formation of a drop at a submerged circular orifice or nozzle will result in a drop size, predicted by equations for determining interfacial tension by the drop-weight method. At the instant a slowly forming drop breaks away from a nozzle, the force balance may be written 

A set of correction factors Dh/Dd) is necessary for exact quantitative results. The model is of course a false one, in that the drop does not break from the nozzle. There is an elongation of a neck of drop fluid connecting the main portion of the drop with that part which is adhering to the nozzle (Nl). Rupture is across this neck, often with the formation 

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