Breakup of Bubbles in a Turbulent Flow: Number of Daughter Particles and Their Size Distribution.

0496932 - ÚCHP 2019 FR eng C - Konferenční příspěvek (zahraniční konf.)
Vejražka, Jiří - Zedníková, Mária - Stanovský, Petr
Breakup of Bubbles in a Turbulent Flow: Number of Daughter Particles and Their Size Distribution.
Book of Abstracts. -, 2017. ISBN N.
[International Workshop on Bubble and Drop Interfaces (B&D 2017) /7./. Lyon (FR), 26.06.2017-30.06.2017]
Grant CEP: GA ČR GA15-15467S
Institucionální podpora: RVO:67985858
Klíčová slova: bubble breakup * size distribution * turbulent flow
Obor OECD: Chemical process engineering

The breakup of air bubbles in a turbulent flow of water is studied experimentally. Water flows from an array of coaxial nozzles, generating intensive turbulence, and then flows downward through an experimental cell. Bubbles (1.8 to 5 mm) are injected in the bottom part of the cell and rise towards region with more intensive turbulence, where they break. The breakup events are recorded by means of a high-speed camera. The velocity field in the cell is measured by PIV. The local dissipation rate is estimated using large-eddy PIV technique. From recorded movies, breakup frequency, number of daughter bubbles is determined and their size distribution is established. Mean number of daughter bubbles depends mostly on the breakup Weber number (We). Breakups are observed for We exceeding 0.5, though they are rare at this low We. Till about We ≈ 2, most breakups are binary; then the mean number of daughters increases.

Trvalý link: http://hdl.handle.net/11104/0289535