This image shows one of the flow structures generated from the
collision of two impinging jets with radius of 420um. The rapid flash
illumination reveals a fish-like formation for dilute polymer fluids:
the oval sheet with rims corresponds to the fish head, drops on thin
ligaments to its body, and bigger free drops at the end to its tail.
The viscoelasticity of the polymer in the fluid resists detachment of
the drops from the ligament. This image was adjusted for hue and
contrast, and rotated by 90 degrees for effect.
Sungjune is doing a PhD at Engineering department.
"We are particularly interested in the formation of a liquid sheet which then breaks up into a regular succession of longitudinal jets and droplets, a so-called "fluid fishbone". The fishbone phenomenon provides a simple and visual tool to evaluate the properties of inkjet printing fluids with which the fishbone structure sensitively varies."
The image was taken using a Nikon D40X with a 105mm lens and a Xenon flash lamp with ~1us duration.