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Page 1: OpenFOAM for marine hydrodynamics CFD - foam … · resources, CFD for marine hydrodynamics is gaining in popularity and slowly replacing traditional methods: experiments and poten-tial

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Priručnik grafičkih standarda za oblikovanje vizualnih identiteta sastavnica

Sveučilište u ZagrebuVizualni identitet

Znak SveučilištaVerzija 2c/b pozitiv

2.2.

Crno – bijeli pozitiv znaka Sveučilišta u Zagrebu (verzija 2) standardno je reproduciran u crnoj boji Pantone Black, odnosno njenom cmyk ekvivalentu. Detaljne specifikacije nalaze se u poglavlju Program boja Priručnika grafičkih standarda za oblikovanje vizualnih identiteta sastavnica.

Radi kvalitete i preciznosti reprodukcije, znak Sveučilišta nije dozvoljeno rekonstruirati (precrtavati, skenirati...) Vektorizirani znak nalazi se na elektroničkom mediju koji je sastavni dio Priručnika grafičkih standarda za oblikovanje vizualnih identiteta sastavnica.

korekcija znaka za smanjenje od 14 mm

FSBUniversity of Zagreb

Fakulty of Mechanical Engineering and Naval ArchitectureDepartment of Energy, Power Engineering and Environment

OpenFOAM for marine hydrodynamics CFD

Vuko VUKCEVICInno GATIN

ABSTRACTThis poster presents the capabili-ties of the OpenFOAM’s Naval Hy-dro pack for marine hydrodynamicsCFD simulations developed withinProf. Jasak’s CFD group.

The CFD model is used for accuratesimulations regarding:

Steady resistance with dynamicsinkage and trim,Seakeeping in head and oblique,regular and irregular sea states,Self propulsion with modelled anddiscretised propellers,Manoeuvring:– Turning circle,– Zig–zag tests,– Crabbing.

Versatile, robust and efficient simu-lations are enabled with:

Ghost–Fluid–Method: accuratetreatment of discontinuities at thefree surface,Interface capturing: Volume–of–Fluid or Level Set Method,Solution decomposition: calculat-ing perturbation around potentialflow solution,Domain decomposition: prevent-ing wave reflection,Semi–monolithic approach: im-plicitly coupled pressure equationand rigid body equations.

Steady resistance simulations

Rapid steady resistance simulations areroutinely performed to aid the design ofships in order to minimize fuel consumption.Image presents wave elevation for threedifferent bow shapes, where the resultshave been obtained within twelve hours,including meshing, case set–up, simulationsand post processing.

Seakeeping simulations

Fully non–linear CFD seakeeping simu-lations are becoming increasingly utilisedbecause of their ability to accurately cal-culate added resistance of ship in waves.Reliable estimate of transfer function canbe obtained within few days using a modestHPC workstation (64 CPUs).

0.6 0.8 1 1.2 1.4 1.6 1.8 2Dimensionless wave length, λ/L

PP

0

5

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Tota

l re

sist

ance

coef

fici

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CT · 1

03

Mean, navalFoam

Mean, swenseFoam

Mean, EXP

First order, navalFoam

First order, swenseFoam

First order, EXP

C1 C2 C3 C4 C5

Oblique wave simulations with roll motionand forward speed do not represent a diffi-culty as opposed to potential flow methods.

Full scale self–propulsion

One of the main benefits of CFD is its abilityto calculate full scale flows without the needfor error prone extrapolation of results. TheNaval Hydro pack has been recently usedto calculate the self–propulsion point for a138 meters long general cargo carrier withconstant propeller revolution rate.

0 100 200 300 400 500 600 700 800Time, s

11.8

12

12.2

12.4

12.6

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13.6

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Forw

ard s

pee

d, kn

navalFoam, 7M mesh

navalFoam, 11M mesh

Sea trial, measured speed on 1st run

Sea trial, measured speed on 2nd run

ISO 15016 speed

Reference for sea trial measurements and results:Dmitriy Ponkratov, Lloyd’s Register: Workshop on Ship Scale Hydrodynamic Computer Simulation, November 2016

Manoeuvring: turning circle

Actuator disk model allows fast CFD simu-lations of different manoeuvres. Using theactuator disk model and deflected rudder,tactical diameter of the KVLCC model hasbeen calculated.

Conclusion

With increasing availability of computationalresources, CFD for marine hydrodynamicsis gaining in popularity and slowly replacingtraditional methods: experiments and poten-tial flow based numerical methods.

Acknowledgements

We are grateful for our industrial sponsors:Hyundai Heavy Industries and Bureau Ver-itas for supporting the development of theNaval Hydro pack.

8th Floor CFD@FSB

Zagreb, 2017Supervisor: Prof. Hrvoje Jasak

www.fsb.hr/cfdFeel free to contact us at [email protected] and [email protected], or take a look at our YouTube channel: 8th Floor CFD@FSB.

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