Annular Sheet Instability & Atomisation

Daniel Duke, Damon Honnery & Julio Soria
Laboratory for Turbulence Research in Aerospace & Combustion (LTRAC)
Department of Mechanical & Aerospace Engineering
Monash University, Australia

This movie shows the instability and primary atomisation of an annular water sheet under the influence of dual co-flowing air streams both inside and surrounding the outside of the sheet.

The airflow is axial (ie. has no swirling component). The sheet is 1.5mm thick and the whole nozzle is about 7cm in diameter. The images were taken using a PCO DIMAX high speed camera at 2000 to 5000 frames/sec, and slowed down so that the oscillations in the sheet surface can be seen. To the naked eye, at high velocity the spray appears as only a blurry mist. By slowing down the process, we can observe the incredible detail and complexity inherent in something which we rely on day-to-day, ie. the transformation of a solid mass of fluid into a mist of droplets. (ie. aerosol cans, pump spray bottles and fuel injection in cars , trucks and aircraft).

This research was supported by the Australian Research Council through a LIEF grant LE100100222.

This video may not be reproduced without permission. (c) 2011 Daniel Duke

This film was made using iMovie '11 on a Mac

Category:

Science & Technology

Tags:

• fluids
• fluid
• mechanics
• atomization
• sprays
• physics
• Instability