Navigation : Top / Research / Bubble Charasteristics and Gas Transfer in the Surf Zone
* Introduction [#yc943917]

Ocean surface gravity wave propagation from offshore to shoreline is often regarded as a single phase flow using potential flow theories or the Navier-Stokes equation. Generally, the single phase flow approach to the ocean wave is successful for simulating wave transformation in the coastal area. However, waves steepen and break due to the bottom bathymetric effects in the near shore. The wave breaking create dense plumes of bubbles, and dissipates energy and momentum. An accurate estimate of bubble size and population distributions in the surf zone is important for understanding two-phase flow characteristics, solving engineering problems and environmental mechanisms of the coastal area. Recent photographic studies have illustrated the disintegration of entrapped air cavities divided into bubbles. However, there are unexplained aspects of the problem, such as enhanced bubble populations in salt rather than freshwater scale effects of void and bubble size distribution in the laboratory experiments, and the relation between void fraction and turbulence.

#ref(http://sauron.urban.eng.osaka-cu.ac.jp/~mori/research/bubble_surfzone/wave_breaking_small.jpg)

** Collaborators [#jf37a711]
- Hiroaki Kashima, OCU
- Satoshi Nakagawa, OCU

This project has bee started since 2004.

* Results [#o312a93f]
** Experimental Results [#f3a0a4b3]
- [[English:http://sauron.urban.eng.osaka-cu.ac.jp/~mori/research/bubble_surfzone/JGR_bubble]]
** Mathematical Modeling [#g51d0b4a]

* References [#va25cfd4]

** This Project [#y4439ef3]
- Mori, N., T. Suzuki and S. Kakuno (2007) Noise of acoustic Doppler velocimeter data in bubbly flow, Journal of Engineering Mechanics, American Society of Civil Engineers, in press (will be apeared in January issue).
- Kashima, H., N. Mori and S. Kakuno (2006) `Temporal-spatial relationship between air bubbles and turbulence in the surf zone', Proceedings of the 30th International Conference on Coastal Engineering, ASCE.
- Mori, N., Kakuno, S., T. Suzuki, Y. Ohnishi (2005) `Experimental study on bubble and turbulence relations in the surf zone', Third Asia Pacific Coasts 2005: APAC2005, pp.1841-1856.



** Others [#r0f7f610]
- [[References of air-bubbles of surf zone breaking]]