Lab. y. Scheepsbouwkund

TecInkche Higccknn1

Deift

MARIN. Holland's well knownMaritime Research Institute Nether-lands, lias facilitics in Wacningcn andin Ede. some 40km east of Utrecht.The research institute operates a widerange of model test basins, marinesimulators and computer systemslinked to a CRAY-XMP super compu-ter.

"It was in fact this conibinationwhich enabled MARIN to become oneof the world's leading developers ofmaritime software." says Henk J.J.van den Boom. Head Applied Hyd-rodynamics Research & DevelopmentDivision.

"Also the better understanding wehave gained of the physical behaviourof marine structures after decennia ofresearch within the institute itselfcontributed to the present success,"Van den Boom explains.

Technological toolsGenerally applicable computer

programs for use within the industry atlarge are increasingly replacing thetraditional report on the livclrodynamiccharacteristics of specific structures.The basic question nowadays is how tosimulate - in three dimensions and realtime - the wave induced-motions ofmoored structures. DF vessels orheavy lift operations.

With MARIN's computers andsoftware even the behaviour of pipes,lines and flexible risers can he predic-

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1-lenk Ji, van den Boom,Head Applied Hydrodynamics Researchand Develonnent Division, MA RIN.

(p/iolo: MA RIN)

ted and visualised. The program usedbr this, DYNFLX, is an example ofhow applied industrial research canlead to the development of advancedtech nological tools.

"Co-operation with industry is verystimulating," Van den Boom says."Software is expensive, but companiesoften have similar needs. Oil com-panies and offshore contractors favourjoint development studies - but theyrequire parctical tools, short deliverytimes and reliable support. DYNFLX,

Visualisation ofD YNFLX-results.(phuk,. filA RIN)

Numerical simula-tion offlow around

a cylinder.(p/wto: MA RIN)

6, ¡ro journaal 20, 27oktober1989

for example, was the result of a prog-ram which started in 1984 with re-search into the dynamic tensions inanchor chains.

"At that stage a line was suspendedfrom the oscillating vessel and assumedto move in still water. In the secondphase attention was focussed on bend-ing stiffness and wave forces actingdirectly on the line. There we createdthe link with pipes and rigid risers."

rn'The results formed the basis for thesimulation model for flexible risers inthree dimensions. In early 1989 thelatest version of DYNFLX, incor-porating torsion, was delivered,"

"DYNFLX is the result of fiveseparate projects sponsored by sixcompanies mainly through 1RO. Whocould have foreseen this developmentin 1984? This way of working, espe-cially in co-operation with JRO. isunique in the world. The resultingsoftware is as good as the best packagesproduced in other typical offshorecountries like Norway and the UnitedKingdom." Van den Boom concludes.

UniqueMARIN was founded in 1932 as a

joint research institute for the Dutchshipbuilding industry, the Royal Navyand the State. It offered facilities fortesting both civil and navy vessels. Italso played an important role in theDelta Works, the massive constructionproject of storm barriers to protectHolland against severe storms.

MARIN and the other major marineresearch institute in the Netherlands.Delft Hydraulics. complement each

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ARCHIEFI RO-Research

MARIN, world leader ¡nhydrodynamic software

Software engineering is a high priority of MARIN's Research & De-velopment programme. Both the shipping and offshore industries widelyuse MARIN's application programs. 1RO plays an iniportant role inco-ordinating joint industry projects in this field.

other's work: MARIN concentrateson ships and offshore structures, DeiftHydraulics on coastal works, harboursand shallow water.

Since the development of the NorthSea hydrocarbon reserves began ín the1960s offshore research has played animportant role in MARIN's activities.For some years the MARIN facilitiessuch as the wave and current basinwere unique in the world. Approxi-mately fifty per cent of all offshoremooring systems have been tested atMARIN's Wageningen center.

A large amount of work is currentlycoming from as far a field as Australia.Fixed structures are being investigatedfor the North West Shelf, and floatingproduction systems tested for TimorSea locations.

Dynamic PositioningA major software engineering effort

currently performed by MARIN'sR&D division concerns the simulationof DP vessels. The design. engineeringand operation of the rapidly growingfleet of vessels with advanced stationkeeping abilities requires reliable andaccurate prediction tools. In theDPSIM-developmcnt project,MARIN has integrated current know-ledge on various factors such as wind,wave and current forces, thrusterperformance and DP-control.

"DPSIM clearly demonstrates thepresent day roles of computationalanalysis and model testing," accordingto Van den Boom. "The computerprogram is intensively used for various

IRO-Research

Mini-simulatorbased On real tuneversion of DPSIM.

(//Iou: t!ARIN)

engineering studies. Model tests werenot only used to develop and verify theprogram. but have also been indispens-able in the final stage of each detailedengineering to establish extrenicloads."

For the DPS tM-development thescope was limited to conventional shiptypes such as tankers. The kick-off

7,1ro journaal 20,27 oktober 1989

meeting of the participants in the newdevelopment study for semi submersi-bles. logically named DPSEMI. isalready scheduled.

InternationalMARIN continuously works to

adjust its facilities to current needs.The institute recently adapted itsWave and Current Basin: 60 meterslong and 40 meters wide. This wasdeepened from I . i to 2.0 meters overan arca of 35 x 20 m. At the centre ofthe basin the local depth was increasedto 8.5 meter making it an excellentfacility for realistic wave, wind andcurrent simulation for floating systems- including mooring and riser systemsin water depths of up to 600 meters.

The institute attracts a lot of interna-tional attention. Van den Boom says."Sixty per cent of our clients comefrom abroad, including the mci-easingnumber of foreign participants withinthe 1RO projects." In spite of heavycompetition in the field, he has nodoubt that MA Rl N will maintain itsleading position - because of theknowledge it has becii built up overthe years. u

Turret-moored storage tanker andexport tanker in the Wave uiid CurrentBasin. (,1u.i: '.14 RIN)