Experiencing the Naruto Whirlpools скачать в хорошем качестве

Experiencing the Naruto Whirlpools

The Naruto whirlpools (Natuto no Uzushio) take place on the Southern side of the Naruto Strait (Naruto kaikyo) at the peak of the flood and ebb tidal currents. The Naruto Strait (Naruto kaikyo) connects the Awaji and Shikoku Islands and is 1.3 km wide. A whirlpool is a vortex of vertical axis, with a downward velocity component near its centre. A good example is the bathtub vortex. A related example is the vortex dropshaft. Whirlpools are two-dimensional vortical structures occurring in a turbulent developing shear layer. Such a flow may be approximated by a series of vortices of identical rotational direction advected downstream. Each vortex is affected by the movement of the fluid due to the other vortices. In real turbulent flows, the vortices may collapse and form a new larger vortex of stronger strength and identical rotation direction (i.e. vortex pairing). The process is sometimes called an inverted cascade of vortices (Chanson 2014). It may be repeated further downstream and this yields large vortical structures. I visited the Naruto whirlpools on 17 October 2001 and on 11 December 2015. On 17 October 2001, the meteorological conditions were poor. The waters flowed southwards from the Inland Sea (Setonaikai) to the Pacific Ocean. The whirlpools were best seen next to the Southern bridge pier. I saw the whirlpools, first from the Ohnaruto bridge walkway (uzu-no-michi) and later on a boat. The bridge walkway is about 45 m above the sea level and reaches 450 m from the bridge abutment. From the bridge, I saw a freighter, which became trapped in the whirlpools and vortices, and got stranded (grounded) beneath the bridge around 11:00 am. The boat was still grounded 2 hours later, waiting for the next high tide. On 11 December 2015, the weather conditions were even worse, with strong winds and seas. The whirlpools were complemented by a large amount of breaking waves and sea mist. The Naruto whirlpools are extremely popular in Japan and are considered a major tourist destination. They are fascinating and constitute a seminal illustration of the large-scale coherent structures in geophysical flows. This is relevant to environmental fluid mechanics and applied hydrodynamics. This is further discussed in a number of relevant Youtube video movies in the same channel at: {   / @hubert_chanson  }   Hydraulic Engineering and Applied Hydrodynamics in Hubert Chanson Youtube channel {   / @hubert_chanson  } Applied hydrodynamics [Playlist] Fluid Mechanics [Playlist] Fundamentals of open channel hydraulics [Playlist] Whirlpools - Experiencing Naruto whirlpools {http://staff.civil.uq.edu.au/h.chanso...} Acknowledgements Hubert CHANSON thanks many people including: Ms Ya-Hui CHOU, Bernard CHANSON, Nicole CHANSON, André CHANSON, Professor Shin-ichi AOKI, Professor Setsuko WAKABAYASHI, Mr Jacques CHANSON, Dr T. NISHIMURA, Dr ICHIMIYA, Professor Richard BROWN. References VAN DYKE, M. (1982). "An Album of Fluid Motion." Parabolic Press, Stanford CA, USA, 176 pages. GJEVIK, G., MOE, H., and OMMUNDSEN, A. (1997). "Sources of the Maelstrom." Nature, Vol. 388, 28 Aug 1997, pp 837-838. NISHIMURA, T. (1986). ""The Tidal Whirlpools Encountered in the Naruto-Strait." K. Sanbunsha Publ., Tokyo, Japan, 145 pages. CHANSON, H. (2002). "Whirlpools. Experiencing Naruto Whirlpools." IAHR Newsletter, Vol. 40, No. 2, pp. 17 & 28-29. CHANSON, H. (2014). "Applied Hydrodynamics: An Introduction." CRC Press, Taylor & Francis Group, Leiden, The Netherlands, 448 pages & 21 video movies (ISBN 978-1-138-00093-3).