Title: Liquid Drop formation from Capillary Water-Jet:

Article Contributed by: Gaurav Singh
Education: B.Tech & M.Tech in Aerospace Engineering, Indian Institute of Technology (IIT), Madras, India
Email: opticaltrek@gmail.com

A Brief write-up:

Water drop formation takes place due to competing gravity and surface tension forces. When the gravity force exceeds the attaching surface tension force, the liquid is pulled in the form of a long thread, ultimately leading to necking and breakup [click for picture] . Gravitational force becomes significant only in case of large drops and becomes insignificant for very small(order) drops [Ref: “Atomization and Sprays” by Arthur H. Lefebvre]. Different kind of structures are formed during breakup. One of the well-known drop structure formed is ‘satellite drops’. Satellite drops are formed by the break up of the ligament that connects two capillary drops (or one capillary drop to the jet). They are called satellite drops since they look like smaller satellites near the bigger drops that form from capillary instability. The application of formation of satellite drops is exclusively found in charged ink jets (printers), wherein continuous jet breaks into bigger drops and later into further smaller satellite drops. The experiment which I did, was mainly intended to see different structures/shapes formed during a capillary water jet break-up. The size of satellite drops is much (an order) smaller than the drops formed by capillary instability from the jet. I think the small drops in picture [9th image & 11th image] seems to be the only satellite drops.

**Picture 11:** Satellite drop formation, these drops are much smaller(order) compared to main capillary drops break up

Pictures attached below are captured using Nikon DSLR D3100. If you would like to see high speed videos imaging(videos at very high frame rate/slow motion), please visit this page: The Opitical Trek: High Speed Imaging.

This Picture above is compiled from images from a high speed camera (Phantom) — This last Picture is compiled from images from a high speed camera (Phantom)

For addition/corrections/suggestions please comment or email: opticaltrek@gmail.com

4 thoughts on “Satellite Drop Formation”

Gaurav, its really great. Now i am taking a course on atomization and sprays. Indeed your photography is really inspiring to learn more into the stability analysis! Thanks a lot.

Gaurav Singh

February 25, 2014 at 22:52

Thanks Vishnu…! Are you doing Atomization and Sprays under Mahesh Sir? Did he show some of my pics in class?

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Yes. amazing the shape of the drops. Fascinates me to.

The Optical Trek

April 17, 2016 at 15:18

Thanks a lot Filip. If you would like to contribute your experiments or images/sample photographs with new information please send to email: opticaltrek@gmail.com

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