Drop formation - an overview

We give a brief description of the technological challenges underlying the dynamics of drop formation, noting that a number of significant early advances are associated with the TH Dresden. In particular, to understand the size distribution of drops, one has to consider the non-linear dynamics leading up to the point where the radius of the fluid neck goes to zero. In this pinch-off region, both the neck shape and the velocity inside it are described by scaling laws, which we investigate from the point of view of dimensional analysis. We consider the crossover between different scaling regions, and briefly discuss more recent developments. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.