Newsletter 2Vo l u m e 1 9 / 2 0 0 2 ( S u p p l e m e n t t o J H R - Vo l 4 0 - N o 2 )

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The Role of PractitionersThis article by Prof. Jean Jacques Peters is based on a presentation made at theInternational Colloquium “Knowledge Transfer for Environment Water” organised in Delft,The Netherlands in June2001 as part of the EUETNET 21 project. Thistext analyses the gapbetween education,research and practice inthe water-field and thedifficulties in bridging thisgap.Continues on page 20

Whirlpools.ExperiencingNarutoWhirlpoolsDr. Hubert Chanson writes on the fascinating topic of whirlpools with a special focus on the Naruto StraitWhirlpools.Continues on page 28

13th Arthur Thomas Ippen AwardFor outstanding accomplishment in hydraulic engineering and research

12th Harold Jan Schoemaker AwardFor the most outstanding paper in the Journal of Hydraulic Research

John F. Kennedy Student Paper CompetitionInvitation To Participate In The John F. Kennedy Student Paper Competition during The 30thIAHR Biennial Congress, Thessaloniki, Greece 24-29 August 2003.

Find more details about the founding statement and rules of these IAHR Awards on page 19

Naruto whirlpools on 17 October 2001 - Street ofvortices with a freighter in the background, viewfrom the bridge during the ebb

Convocation 2002 General Members Assembly

View of Puerto Villaroel har-bour, on a meander loop ofthe Ichilo river, BolivianAmazon region.

Call for nominations

All IAHR members are cordially invited toattend the IAHR General Members Assemblywhich will be held on July 5th, 2002 inCardiff, UK.Venue: Cardiff UniversityTime: 14:00 – 15:00

AGENDA■ Opening■ Announcements■ Minutes of the 2001 General Members

Assembly, September 21st, 2001, Beijing,China (published in Issue 1, 2002)

■ 2001 Financial Report■ 2001 Annual Report Association Activities■ Any Other Business■ Closure

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By H. ChansonReader, Environmental Fluid Mechanics,Department of Civil Engineering, TheUniversity of Queensland,Brisbane QLD 4072, AustraliaEmail: h.chanson@mailbox.uq.edu.au - Url: http://www.uq.edu.au/~e2hchans/

The Merriam-Webster’s Collegiate

Dictionary states that a whirlpool is “watermoving rapidly in a circle so as to producea depression in the centre into whichfloating objects may be drawn”. Basicallya whirlpool is a vortex of vertical axis, witha downward velocity component near itscentre. A good example is the bathtubvortex [1]. In coastal zones, whirlpools areproduced by the interaction of rising and

falling tides. They are often observed atthe edges of straits with large tidalcurrents (Table 1). The vortex (whirlpool) isa coherent structure typical of shear flowswhere there is a velocity difference acrossthe shear layer. It affect the surroundingflow and water can be seen going backand forth across the shear layer betweenvortices.Whirlpools are sometimes calledMaelstrom, after the Norwegian current.The Maelstrøm is a strong tidal current ofthe Norwegian Sea in the Lofoten islands[2]. Flowing between the islands ofMoskenesøya (North) and Mosken (South),it has a treacherous current. Strong localwinds make the passage additionallydangerous. The word maelstrom enteredthe English language via fiction novelistswho exaggerated the current of thechannel into a great whirlpool (e.g. JulesVERNES, in “Vingt Mille Lieues sous lesMers”). In English, the word “maelstrom”designates a large, fatal whirlpool,engulfing vessels and men, or a figurativeapplication of the idea. Notable oceanic whirlpools include thoseof Garofalo along the coast of Calabria insouthern Italy, and of Messina in the straitbetween Sicily and peninsular Italy.Whirlpools near the Hebrides and Orkneyislands, and in the Naruto strait betweenAwaji and Shikoku islands, are also wellknown. In Western Scotland, theCorryvreckan whirlpools are said to be“one of the most notorious stretches ofwater anywhere around the British Isles”.The Naruto Strait (Naruto kaikyo) connectsthe Awaji and Shikoku islands, Japan. Thestrait is 1.3 km wide. The tide is semi-diurnal and the tidal range may be up to1.7 m. The differences in tidal levelsacross the strait may reach 1.5 m withcurrent speeds exceeding 9 knots (4.6

wide range of initiatives. Again, to namebut a few, NWRI is involved in planningthe sixth phase of the UNESCOInternational Hydrological Programme,2002-2007, a NATO Advanced Workshopon Urban Water Management, theUNESCO IntergovernmentalOceanographic Commission, the ArcticMonitoring and Assessment Programme(AMAP), and an OECD initiative on

endocrine disruptors. Researchers andresearch managers also have collaborativeprojects with numerous universities andresearch institutes in North America,Europe and around the world. And ofcourse, there is the long-standinginvolvement with IAHR – with whom NWRIstaff and management look forward tomany more years of fruitful co-operation.For more information on the National

Water Research Institute and its staff, visitthe website at www.cciw.ca/nwri

Jiri Marsalek, Project Leader, Urban Water Management,NWRISecretary IAHR –IWA Joint Committee onUrban Drainage

Naruto whirlpools on 17 October 2001 - View from a tourist boat, looking upstream at a whirlpool in fore-ground and the grounded ship in the background

Whirlpools. Experiencing Naruto Whirlpools

m/s) on the Northern part of the Strait. Thenotorious “whirlpools” (uzu-maki) takeplace on the Southern side of the Strait atthe peak of the flood and ebb currents.The flow (or flood) and ebb are also calledsouthward and northward currentsrespectively.The writer visited the Naruto whirlpools onWednesday 17 October 2001. Themeteorological conditions were poorbecause the centre of Typhoon No. 21 waslocated few hundreds kilometres South ofJapan. The ebb current was maximumaround 12:20 pm. The waters flowed fromthe Inland Sea (Setona Kai) to the PacificOcean. The whirlpools were best seennext to the Southern bridge pier. H.CHANSON experienced the whirlpoolsbetween 10:45 am and 12:45pm, first fromthe Ohnaruto bridge walkway (uzu-no-michi) and later in a boat (Fig. 1 and 2).From the bridge, the writer saw a freighterwhich became trapped in the whirlpoolsand vortices, and got stranded (grounded)beneath the bridge around 11:00 am. Theboat was still grounded 2 hours later,waiting for the next high tide (Fig. 2).Figure 1 shows a street of vortices with afreighter in the background. Thephotograph was taken on the Southernend of the Strait, 45 m above the sea andabout 450 m from the bridge abutment.The main current flows on the left of thevortices. Although the turbulence appearsless intense, the ship was subjected to afaster current and to the effects of large-size cauldrons. Figure 2 presents a view

from downstream. A whirlpool is visible inthe foreground of the photograph. Thegrounded freighter (green hull), strandednext to the bridge pier, is visible in thebackground.Full details of the visit of Naruto whirlpoolsare at :{http://www.uq.edu.au/~e2hchans/whirlpl.html}. The website includes furtherphotographs and links to relevant websiteson whirlpools.

AcknowledgmentsThe writer acknowledges the help andsupport of Mr B. CHANSON, Ms Y.H.CHOU and Dr S. AOKI.

References[1] VAN DYKE, M. (1982). “An Album ofFluid Motion.” Parabolic Press, StanfordCA, USA, 176 pages. [2] GJEVIK, G., MOE, H., andOMMUNDSEN, A. (1997). “Sources of theMaelstrom.” Nature, Vol. 388, 28 Aug1997, pp 837-838.

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FMTM20018th International Symposium on FlowModeling and Turbulence Measurement

The 8th International Symposium on FlowModeling and Turbulence Measurement(FMTM) was held in the CentralAdministration Building of the NihonUniversity, located in the central Tokyo,Japan, December 4-6, 2001. The first onewas held in Paris in 1982 and sevensymposia on the same subjects have beensuccessively held since then every two tothree years, in Iowa City (USA), Tokyo(Japan), Wuhan (China), Paris (France),Tallahassee (USA), and Tainan (Taiwan).This symposium was sponsored by IAHRand co-sponsored by American Society of

Strait :

Other name(s) :

Country :

Location :

Tidal range :

Strait width :

Current speed :

Whirlpools :

Access :

Naruto

Naruto kaikyo

Japan

between Awaji andShikoku islands

up to 1.7 m

1.3 km

up to over 9 knots(4.6 m/s)

Large whirlpools on the Southernend during ebb

Views fromOhnaruto bridgeand from touristboats

Maelstrom

Moskstraumen

Norway

between LofotenPointand Vaerøyisland, Lofotenislands

-

8 km

up to 7 knots(3.6 m/s)

-

-

Saltstraumen &Sandstraumen

Saltfjord &Skjerstadfjord

Norway

50 km North ofBodø

up to 3 m (?)

-- (Sandstraumen)-- (Saltstraumen)

-

-

Two straits : theSandstraumen andthe SaltstraumenView from thebridge crossing

Corryvreckan

Corrievrekin,Charybdis

Scotland

between Scarbaand Jura islands,Western Scotland

-

-

up to 9 knots(4.6 m/s)

-

-

Table 1 - Characteristics of large whirlpools

Committee and section members’ get together