Collisions of a string of water drops on a water jet of equal diameter

The collision between a water drop and a water jet of equal diameter was experimentally studied. The collision outcome was found to depend on the impact parameter, the cross-jet Weber number, and the along-jet Weber number. Five collision outcomes; namely, segmenting coalescence, clinging coalescence, stretching separation, bouncing, and splashing were observed. The lower impact parameter limit for stretching separation to happen was found to decrease with increasing cross-jet Weber number. For a constant cross-jet Weber number, as the along-jet Weber number increases, the collision produces first segmenting coalescence, and then clinging coalescence with diminishing jet deformation. Bouncing happens for small cross-jet and along-jet Weber numbers, and small impact parameters. Simple energy models for segmenting coalescence and stretching separation were developed with their empirical constants determined from experimental data.