Jo Pinkster PMH bv - NTNU

Jo Pinkster PMH bv

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Olympic

HMS Hawke

An incident in 1911

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A first analysis of ship-ship interactions during overtaking Anon, Nature , 1912

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Another incident 1912

Titanic

New York

Docking – undocking

Bank suction effects

Meeting ships

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Overtaking ships

Lightering operations

at sea

Vessels passing by or

over underwater

obstructions

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Full scale (“on the job” training)

Model tests (manned (Port Revel)/ unmanned)

Real time manoeuvering simulators (man on the bridge)

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A ship manoeuvering simulator

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Based on mathematical model of single manoeuvering vessels in open water

Present : Hydrodynamic effects of other ships, bank suction etc. computed off-line and put in data-base for interpolation during real-time simulation runs

Ambition: Compute these effects “ON THE FLY” based on appropriate mathematical model which can deliver the required forces on a vessel sufficiently fast to qualify as being in “REAL TIME”

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Based on 3-d potential flow (inviscid, incompressible etc)

Non-lifting bodies

Double-body solution (low Froude number)

Multi-body (Ships and port structures)

Zero-order panel method , Rankine sources. Similar to Korsmeyer et al (1993)

Shallow water effects , Grue & Biberg(1993)

Force equations suitable for transient motions, Faltinsen & Xiang(2011)

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Panel models of typical vessels

Container vessel : 3000 panels Tanker : 900 panels

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Large vessel backing out of dock

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Time (s)

Yaw

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kN

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Forces on moored vessel. Case 1.07

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ay (

kN

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Normally carried out using desk top type computer based on standard CPUs using single or multi-cores.

The problem at hand requires computing power only available on multi-CPU clusters.

Nowadays inexpensive alternative available using GPUs with 2000 computing cores or more on a single plug-in unit for desk top computers.

We have chosen a combination of standard CPU + GPU to obtain the necessary performance. At present the code runs on a stand-alone pc communicating with the main simulator computer.

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Coupling of Delpass with MARIN’s real time simulator 18

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The next step : Incorporate ‘real’ channel shape based on bathymetry data

Coupling the potential flow code to the simulator has been

realized. The GPU makes it possible to compute interactions faster and for more complex geometries.

The methodology is being used regularly for real time ship simulator studies.

There is a need for validation of results against experimental data.

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