Finding the hull form for given seakeeping characteristics

Date Author Address

September 2005 Kapsenberg, G.K.

Delft University of Technology Ship Hydromechanics Laboratory

Mekelweg 2, 26282 CD Deift

TUDe Ift

Deift University of Technology

Page lof 1/1

Finding the hull form for given seakeeping

characteristics

by

Kapsenberg, G.K

Report No. 1457-P

2005

Presented at the 12th International Congress of the

mt. Maritime Association of the Mediterranean, IMAM, Lisboa, Portugal, ISBN: 0 415 39036 2

pROCEEDINGSOF THE i2 _{INTERNATIONAL CONGRESS OF ThE INTERNATIONAL} MARITIME ASSOCIATION OF THEMEDITITERRANEAN (IMAM 2005), USBOA,

POAITUGAL, 26-30 SEPTEMBER 2005

Maritime Transportation and

Exploitation of Ocean and

Coastal Resources

Volume 1: Vessels for Maritime Transportation

C. Guedes Soares, Y. Garbatov & N... Fonseca

Instituto Superior Técnico, Lisbon Portugal

Taylor & Francis

BALKEMA Proceedings and Monographs

Copyright © 2005 Taylor & Francis Group pic, London, UK

All rights reserved No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, o, transmitted in any form or by any means, electronic. mechanical by photocopying

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operation or use of this publication and/or the information contained herein Published by: raylor & Francis/Balkema

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ISBN (Set): 0 415 39036 2

ISBN volume 1:0415393736

ISBN volume 2: 0415 393744 ISBN cd-mm: 0415 39433 3

Maritime TmnsportationandEj loitation of Ocean and

GOataiResources - Guedes Soares. (3arbatov & Fonseca (ads)

© 2005 Taylor& Francis Group, Londòn, ISBN 0415390362

Table of Contents

Preface

XVII

Volume i - Vessels for Maritime Transportation

1.1

Hydmdynamics

Investigations on standards fox ship rnanoeuvring performance at slow speed inconstrained space 3

T Abramawicz-Geì'igk

Numerical study of the effects of hull shape and launching condilions on the behaviours

ofa free-fall' lifeboat:duringwater entry 9

M. Arai, Y Tsukioka,S. Tozawa & K Yamane

Simulationof a spring line applicatiónto enhance berthmgfunberthing manoeuvres 17

A Anyszuk

Numerical' assessment of operational behaviour ofhigh-speed, POD-driven large ships ₂₇

ZAyaz O. Tumn&D. Vasralos

Largeainplitude slow motions of mooring systems 37

MM Bernitsss&.J.RL Matsuura

-Cost effective fiill!scaleobservation and recordingof propeller blade cavitation 53

N Bobánac, M Sambolèk, S RadU & I Beatovk

Weakly non-linear wave induced loads in thnedomain for high-speed miiltihuil vessels ₆₁

D Bruzzone & R Gancia

Staggered Catamarans: experimental! data and feasibility study for environment friendly service ₆₉

F Caprio A' Migali & C Peina

Second-order diffraction by asui-facepiercing truncated compound cylinder 77

1K cJzajigeorgiou& SA. Mavrakos

CEli analysis on the flyingshapeofmodern yacht sails ₈₇

GE C1a1th&WIIeLen

Multi-body systems in waves - impact of hydrodynamiccoupliuigoninotions ₉₅

G.FClaucs &K Jacobsen

Hydrodynaniiccoeflicients and;forces on catamarans inshallow water 107

N Dahcsi M Chagdali &A Hémon

Nonlinear waveresistance computations:asa dèsign tool inhull form improvement stUdies 113

DB. Danisman & O Gären

Sorne parainetersinfluencingthe accuracyof the wave pattern resistance!deteimination 121

N Deglull A Weiner &T Stasic

Numerical calculatiànof:ship's propulsiónmechanismofWeis-Fogh-type byvortex method 129

KD Ro H K Kang TN Kong & MII Kang

Effect of heel angle on global hull girder loads and ship motions

L. Foire & 1 ¡accarino

Experimental and numerical hydrodynamic coefficients of a conlainershipin

large amplitude heaving and pitching N Fonseca C Guedes Soares & A Morón

Catamaran wave resistance and central wave cuts for CFD validation

A S. Iglesias, R Zamora D Fernández & CL Pavón

Parametric study on relative wave height of ships in the rough sea

Y ¡noue NM Golam Zakaria & R Nakai.

Time domain computation of the wave making resistance of ships

F Kara

Computer simulation of interaction of tanker and offloading device

arranged at platform or single point mooring SL Karlinsky, VO Mrykin & MA Kuteynikov

On the ship maneuverability of tandem arrangement CRP pod propulsion system i Kayano T Haraguchi, l Tsukada & T Kano

Experimental verification ofan advanced deck wetness prediction method

R Kishev V Rakitin. V Chalakov & A. Maron

Manoeuvring characteristics of full-bodied ships with POD propulsion

L K KobylM ski & .1 Nowicld

Numerical simulation of low speed flows past under water vehicles

EA Korany, E H Atta B YBayoumi & MA. Korb

Some aspects of seakeeping of the floating body with attached pendulum

S Malenica IM Orozco & X-B. Chen

Hydrodynamic characteristics of two concentric surface - piercing floating

SA Mavrakas

Energy saving and dynamic stability of planning hull due to hydrodynamic

MA. Mosaad, MM Gaafa,y&IA Amin

A coupled third order model of roll parametric resonance MA S Never & CA. Rodriguez

Motion predictions and sea trials of roll stabiised frigate S. Ribeiro e S'uva, N Fonseca, R Pascoal & C Guedes Soares

Full-scale resistance study and analysis of a patrol boat at three different

hull/propeller roughness conditions

CM? Sampaio, AA Russo, K Nishimoto & K Hirata

A practical power prediction of an asyrmnetric catamaran hull form

R. Sampson, M At1ar A Mantouvalos. B Danisman & O Goren

A general expression of the internal friction in the boundary layer

C Simeone

An object-oriented manoeuvering simulation code for surface displacement ships

S Sutulo & C Guedes Soares

Computation of the resistance of a Series-60,Cli 0 6 model under a measured free-surfuce

G Tzabiras & D Ga,vfallidir

vi

circular cylinders

control of trim angles

137 265 273 283 287 295 147 157 167 179 185 189 195 199 207 215 221 229 243 255

Vortex shedding from a circulai cylinder at high Reynolds number 301

(10. Unal& O Gören

A study of the effect of steady flow on the unsteady motion of high-speed craft 309

NXie&D. Vacsalos

CF]) calculations on the sail-like three dimensional airfoils 317

i Yoo, ¡R Park i Kim. H A/rn & SR Van

Ship load model on large amplitude waves 327

A. Zamarin

HydrodynamiC experiments on a catamaran hull with a central bulb,

considering its resistance and seakeeping performances ₃₃₇ ¡ Zatts!

1.2

Structures

Fatigue assessment of block joints on passenger ships and a proposal for

innovative technical solutions ₃₄₇

G Bacicchi M Blot M Maestro, A Marinò &A. Toschetti

The use of artificial neural networks to reduce welding distortion ₃₅₇

G.iBruce&MFLighfoot

Optimum design of composite ship panels ₃₆₅

J

hinca, I Gawi!escu D. Boazu & EF Beznea

Some considerations on global ship vibration analysis . 373

J Chirica, V Giuglea O Durnitriu & PR Pencu

Some considerations on the structura] modelling technique of double wan structures ₃₇₉

A. Dimache, D. Olaru M Modiga & L Stoicescu

Experimental snidy of failure in pm-notched beams under transveise impact ₃₈₇

D. M Dimas & C Guedes Soarer

Modal behaviour of a fÙll-scale deck panel with anti-noise treatments ₃₉₅

A Ferrari&E Rizzuto

Fatigue strength assessment of fillet welds predominantly subjected to throat bending ₄₀₅

WFricke A Kahl&H Paetzold

Effect of truck induced load on welded structural joints subjected to fatigue

Y Garbatov, ¡M Santos & C Quedes Soares

Fatigue damage assessment of a newly built FPSO hull ₄₂₃ Y Garbatov, S Tomasevic & C Guedes Soares

Effect of the shape of localized imperfections on the coilpase strength of plates 429

C Quedes Soares, A R Teixeira, kM Luis, T Quesnel. Pf Nikolov, E Steen

JA Khan,

C Toderan CD Qlaìu A Bollero & M Taczala

Evaluation of nonlinear behavior for a typical stiffened plate panel to lateral load in ship structures 439

L Gusha

Some finite element estimates of ship collision event J Kajarte-Rudnitskj, R Varst.a & J Matusiak

Structural response of intact and damaged stiffened plated structure for ship structures

IA. KhanRK Das &YZheng

vn

413

447

Qualitative design assessment of crashworthy structures 461 A Kianac S Ehlers K Tabri S' Rudan & i Broekhujj.sen

Strength tests of steel sandwich pane) 471

L Kazak

Critical assessment of ultimate hull girder capacity of ships from a

reliability analysis point of view 477

T Moan, HKK Amlashi & G Dong

-Idealization of the plating complex initial deflections 487

RI Nikolov & A K Andree

A comparative study on the collision resistance of single and double side skin bulk carnets 497

O Ozguc RK Das & M Samuelides

Comparison of the 31F and JBP drafts with other class suIes 507

C M Rizzo & E Rizzuto

Fatigue strength assessment of a weld connection misalignment in LPG bilobe cargo tanks 521

S Rudan & I Senjanovh

Reinforcement of inipesfect biobe cargo tanks in liquefied gas carriers 527 I Senjanovth, S Rudan &A.M Ljuftina

Impact on single-skin marine composites 535

L S Sutherland & C Guedes Soarer

Corrosion behavior of shipbuilding high strength steel welds employing electrochemical methods 543

D Tsiourva. L i Dimarato.s. Di PantelEr & Vi Papazoglou

Rationalizing the design of ice strengthened side structures 549

G Wang R Basu,D Chavda&SLiu

Numerical methods solving dynamic finite element equations 559

IT Xìng

Powes flow analysis and applicationsfoEship vibration and control 569

YR Xion J T Xìng & WG Price

Superstructure deck effectiveness ofthe generic ship types - a concept designmethodology 579

Y Zanic .1 Andric & P Prebeg

Environmental factors affecting the time dependent corrosion wastage of marine structures 589

A Zayed Y Garbatov. C Guedes Soares & G Wang

Effects of hull defOrmations on ship displacement 599

K Ziha S. Goles A Radico & S Maksimovic

1 .3

Machinery and propulsion systems

Low emission propulsion plants for urban and coastal transportation 609

F Balsamo & F Quaranta

Interaction between ship propulsion plant automation and simulation 617.

G Benvenuto, G Cairem. M Figari & U Campora

Effects of fiel quality on two strokes slow speed diesel engines 627

G Benvenuto M Figari & CM Rizzo

Investigation in WHR-boìlez soot fires 635

Flow characteristics of air-caps for tank ventilation ra ships

SErgin

Hydrodynamicsadapration of pre-swirlstators to propellersof high speedmarine cram

MMGaafaiy

Reliability of ship machineryplants and damage chains R Häk/dnen

contra-rotating podded propulsorandits ñulscale model tests

X Kawana,ni, T Kijdo.& N Kawoshinia

Permanentniagnet electric motorsbased shippropulsion system K Kòroman D Linarii, R Milos

& B Rufoji

Development of multi-staged axial flow fans for caigoholds of container ships

S Lee, KS KimH-S Kirn&SH hun

Operational factors triggering off hazards for operatörsof\ship pOwer plants A. Podsiàdlo

Developmentyossibilities.of modern coal-fired marinepropulsionpiata

A testan & Z Parat

Machineryfunction factors triggeringoff hazards for operators of shippower plants W Tare/ko

1.4

Controlsystem

Fuzzy logicand model referenceadaptivecontrol of ship ro11stabilization using finactuatór

FAlarçin

Floating vessels control - mathematical modeling of thewaves

S Manduka

Research environment for motion control algorithms testing of scale ship models on a läke L.. Morawski. i Pomirski &A. Rak

Analysis of recursive neutral networksperformance trainedwith noisy manoeuvring data

L Moreira & C Guedes Soarer

Design of robuststeeringautopilot for ships L. Moreira & C Gueder Soarer

Isolation of theslainming-induced local vibration using fèedback control

M Mosieh &HS El-Kilarn

Roll-Yaw regulationusing stabilizing finsand rudder ¡na disturbance

observer based compensator scheme

R Parcoal, B Rodrigues & C Guedes Soares

The marine systems simulator state-space model representation for dynamically positioned surfacevessels

0 N Smogel4 T Ferez, TI Fassen & AL Sørensen

1.5

Veseldesign

Analysis of cargo offloading operations

ATRALho&RL.L Jij

Seakeeping metarnodeloffast ro-ro ships: RSM or ANNiechnique? 4 D A/kan, G Trincar & R Nabeigoj

763 771 643 651 661 669. 677 685 69] 699 705 715 721 727 733 .745 755 783 789

Design of an AFRAMAX tanker Baltic ice class i A acc to new SwedishFinnish

rules 2002 and model testing results - basic hydrodynamics problems 799

D Bezinovk

First evaluation of the design data for fast ferries 807

T Coppola & C Pensa

On the problem ofthe machinery choice and hull weight assessment

for the design of high-speed vessels 815

T Coppola A Paciolla & E Quaranta

Development ofa Mono-column type unit for harsh environment 823

A R Costa ¡Q Masetli M Cueva, K Nishimoto, G Machado & A Corte Design of the modern cargo ships of restricted navigation area to

Mediterranean and Black Sea region 831

G. V Egorov

Study of the intact stability of a Portuguese Nau from theearly XVII century 841 N Fonseca. TA Santos & 1? Castro

Multi-attribute design optimization of Adriatic catamaran ferry 851

i Grubisic & ¡ Munic

Application of genetic algorithm to s ucural optimisation of high speed craft 859

T Jastrzebsld & Z SelwLsJd

Finding the hull form for given seakeeping characteristics 867

GK Kapsenberg

Optimization and robust investigations in ship design 875 RN Kolev, TR Darn yanhiev & RG Georgiev

Evolution of LNG carrier design 883

.1 Romero & I Mosquera

Multi-objective optimization of fast ferry watertight subdivision 893

TA Santos & C. Guedes Soares

FPSO - Box Shape: A proposed tankers layout 901

¡M Vasconcellos

1.6

Shipyard technology maintenance and repair

Using throughput in approaching shipyard production process design 909

N Fafandjel M Hadjina, T Matuija & V Simone

Simulation foi criteria evaluation in shipbuilding production processlayout optimisation 915 N Fafandjel, D Pavletk & M Hadjina

Some aspects of complex production systems modelling 923

R. Iwañkowicz, .8 Metschkow, T Graczyk & T .Jastrzebsid

Development of underwater technology for maintenance of off-shore objects 929

S' Kra!j ZKo2uh&I Garafré

Production technology peculiarities of ships' body components from sheetproducts 935

VF Kvasnytskyy, VV Kvacnyts/cyy. G V Egoivv, Zh. G. Goloborod ko & Iii V Solonkhenko

rhe CAD system and its integration into the shipyard's integral IT system 941

M Milanovic, R Bencic & E. Yitasovic

Mapping the iIÏk)nnation flow through shiprepaii activities, 951

A. Sinha. K Ward & G Bruce

Photogrammetry in the shipbuilding production process ₉₅₉ T Zaplatlé. .1 Kodvanf & B Ljubenkov

Author Index ₉₆₅

Volume 2- Exploitation of Ocean and Coastal Resources

2.1

Maîine environment

On the levels of uncertainty in the estimation of extreme values

G Barbaro &MC Martino

Propagation of water waves through shearing currents in general bathymetry

KA Belibassoiric

High resolution wind modelling Mediterranean extremes

j Cateura, A Sanchez-Arcilla & R Bolaflos

A parabolic equation based on a rational quadratic approximation for surfhce gravity wave propagation followed in curvilinear orthogonal coordinates

M Chagdali & S Mordane

Bispectra and time-frequency spectra of wind waves in the coastal zone

Z Cherneva & C Guedes Soarer

Tests of wave shoaling and surf models in a partially enclosed basin

D.C. Conley&E Rusu

Does linear wave theory support freak waves

S Cosme & P Mónica

Influence of the distribution of the random wave heights on the longshore current velocity ₁₀₂₉

R Gentile & L R Landò

GIS based system to assess sea conditions along specified ship routes ₁₀₃₇

C Guedes Soares & MB. Pacheco

Robust Pareto optimal routing of ships utilizing ensemble weather forecasts

L Hinnenthal & O Saetra

Application of marine radar for real-time ocean wave monitoring R Hosoda, T Kojima, H Susaki, Y Hiraoka & Y Iwasald

lime and spatial variability of parameters of individual waves in a coastal zone 3 Kuznetsov, ¡ V Sapiykina & YS Yuresanrkaya

Formation of extreme storm waves on black sea

S Kuzneuov, I Sapryidna, K Kosyan & O. Purhkarev

A wave forecasting system developed for the Spanish harbors

MG L.alwz&jCCAlbjacJz

Bindcasting and forecasting the probability of freakwave occurrence L Lopaioukhin, A Boukhanovsky & C Gueder Soares

Impact of the upwelling on the sediinentology of the continental shelf of the Agadir Zone - Tarfaya

A Makaouz A OrbL A Agouzoulç ML Bouaamnzni & M Talbi

Filling gaps in wave records with artificial neural networks

O. Makarynsky, D Maka,ynçka E Rucu & A Gavirilov

Modeling wave propagation over a barred beach with the FUNWAVE model

./ Mil-Homens A A Pires-Silva & C.J Fortes

xl

971 981 991 999 1005 1015 1023 1045 1051 1061 1065 1069 1075 1081 1085 1093

Estimation of directional wave spectra from measured ship responses 1103

UD. Nielren

On the stopping criterion to apply the Hubert Huang Transform method to sea wave records 1113

R Pascoal A D. Veitcheva & C Quedes Soares

Wave modeling for \'irtual Environments

i ia

A A. Russo C MR Sampalo & D Taniguchi

Computational strategies and visualisation techniques for the wave modelling

in the Portuguese neaxshore 1129

E Rusu, C. Ventura Soarer & L Rusu

Reanalysis of the wave conditions on the approaches to the Portuguese port of Sines 1137

L Rusu, R Pila, & C Quedes Soares

SOPRO - a software package for wave characteristics in ports 1143

LA Santos, CJE M Fortes, L Pinheiro & M G P/eves

Analysis of wave parameters in extreme wave records 1153

W Suiisz & M Paprota

Reliability of SWAN model simulations for the Black Sea Romanian coast 1159

C VTrusca

Survey of techniques for real-time visualization of the ocean surface 1167

AM Varela & C Quedes Soares

Modelling of the effect of the continental shelf on the marine circulation 1175

M Zarn M Bouammrani M Gowvhane & M Chagdali

2.2

Fïsheies and aquaculture

Preference communication in multiattribute procedures for optirnised ship design 1181

M Bamne E Begovic, C Bertorello &.M Stella

Response from current and regnlar/iiregjilar waves on a typical polyethylene fish farm 1189

A.Berstad&HTronszad

.

Safety of fishermen: risk factor analysis and the influence of vessel nautical properties ¡197 G Boccadwno & A Scamardella

A mathematical model for the dynamics of the towed depressor used in the trolling fishery 1205

K Ebata, S Fuwa H Sano T Hirai;hi &K Yamainoto

Flow characterization around a cod-end 1211

G Germain, 1-VFacq &D Fnou,

Improvement of the "Soft Door", a newly developed mouth opening device for trawls

considering hydraulic dynamics 1217

M Ishizaki, Y ¡noue A. Habano, K Ebata. T Hiraishi & T Kumazawa

Precautionary approach in Baltic herring trawl fishery: the effect of hauling techniques and

engine power on unaccounted mortality estimates 1223

A. íd, vik, T Raid, H Shpilev, L .Jöjv&A L.ankov

The influence of the Albanian sea winds on fishing-boat stability of PV 2KP-400 type 1231

KN Lzpa&KI Ibrahimi

Computation modeling of the moored flexible structures 1239

C W. Lee, HS Kim GH Lee. KY Koo, M 1 Choe, B .L Cha & S. J Jeong

Design and performance of a software based fishing simulator 1245

CWLee MWLeeGHLeKYKoo&MYChoe

A multi-criteria stern trawler selection model using the analytic hierarchy process 1251

HWLeJzeta

Numerical study of the flows incod-ends

D. Marichai&G Massart

New net cage designs to prevent tearing during handliñg ₁₂₆₅

H Moe A Fredhei,n& MA Heide

A source panel modeFof plànktonsarnplér hydrodynamics ₁₂₇₃

FG O'Neill

A quickcstimation ofseakeepiñgchaiacteristics on fishing vessels 1279

F Pérez-Arribas, R Zamora, L Pérez-Rojas &.L Freiria

FEM modeling offlexiblestructures mal eofçables1 barsandnets ₁₂₈₅

D. Pria ur

BendingstifThessof a clamps-connected 2-rings PE fish cage collar 1293 K Vi'kestad & E LIen

23 Maritime transportation and port operation

Benchurarking analysis öf European ports and terminaIs

.p:Ant5o, C GuedesSoare&A Gerretzen

Economic operational studyofthe stockyad andshipment of Ubu Port RC Botter.'Á S. Siquei,a L.R Castro Neto & WR A. Ceciliano On thedevelopment:of new mooring supportsystem

S Hara K Hoshino H Kawashuna T ¡Cano K Tanizawa M Nakamunz H Kaflwwu M Manabe H Saiki & K Ohnô

The Ba ceuroegionstzutegieson1eve1opment of'short seashipping

J Kubiki

An innovative dynamic tanker freight rate index D,k'.Lyridis, RG Zacharìoudakis.& D. Chalzovouio.s

A dynamicregional forastof tanker freight.rates withtheusageof ana1yticaltechniques

DV Lyridis RG Zachar.ioudakis & T Paviidis Sùnulation of container terminal's operations

J Marchai & Z Zhang

Theoretical grounds to evaluate quality of the transport system operation L. Mtdlewski&.M Wompay

An analysis of the European Union porispolicy

NPsarafiis

SustainabIedeveJopmeot of the Port of Lisbon

AC Reis Cunha

R.ole.ofL.NG in Mediterranean, region. New fleet required , 1385

.1 Romero

Model for selecting container yard equipment and stacking formation strategies in container terminals

G.S deSá Peixoto& .RC Botter

Navigation Chaiacteiisticsof the Danube and its influence on the

main dimensions of the river-seashi,s

VSldiljaica & T Baclralié

1259 1303 1311. 1319 1327 1333, 1343 1351 1361 1371 1377 1395 1401

2.4

Coastal and offihore development

Monitoring of the Bulgarian Black Sea beaches 1411

VZ Dachev E V7)fonova & MK S:ancheva

Expanding urban development using floating infrastructures 1417

PB González 4. Alvarez, A. Salamanca & B Alvarez

A study of the effect of an underwater mound on the hydrodynamic

performance of onshore wave-power device 1423

F Gouaud V Rey, R van ¿fooff L Piazzola & G. Tedeschi

Pipeline installed by free immersion in the Black Sea offshore areas 1431

IC Matulea,i Strat&E Rusu

Modelling the effect of wave-current interaction on the sediment transport 1439 L Mouakkir. S Mordane, M Chagdali & H Smaoui

On the feasibility of installing SCR's by the reel-lay method . 1447

TA Netto A Bollo MI Lourenço & R Quaranta

A particle-tracking model of spreading of fine sand sediments 1455

VPenchev, B Savov & Z Theocisaric

Wave energy for oil and gas offshore application 1463

E Ricane M M Pinheiro PR Costa & SF Esrefen

Leirosa sand dunes: a case study on coastal protection 1469

C Schreck Reis. H Freiras & .1 Antunes do Carino

A conceptual design and fünctional assessment of the foaling

container terminal with high activities 1475

T Shinoda N Fukuchi & H Kim

2.5

Safety and neliability

Reliability of port transportation systems related tO their operation processes A Blo!ws. K Kolowrocki & .1 Soszynska

Sensitivity analysis of search area determination mathematical model Z Bureiu

SAFEDOR - risk-based ship design, operation and regulation

¡f Christensen, W Hensel AR de Lucas, PC Saines, R Skjong, T Strang & D Vassales

Hazard identification & risk ranking of AFRAIvIAX tankers by expert judgement

S Delautre S A/au, C Tuzcu N Mikelis & A Papanikolaou

A safety assessment for marine accidents considering mental

stress based on measuring heart sate variability N Fukuchi & T Shinoda

Challenges of modern assessment of safety of ships in critical conditions Options for preliminary design

M Gerigk

Selected problems and methods of navigational risk assessment

L Gucma & Z Smalko

Specific features of the reliability maintenance of lashings of the deck heavy-weight cargoes and bulk cargoes in flexible containers

VV Kozlyakov, IR Davydov & A. V Stas.ytsky

1487 1497 1503 1511 1521 1529 1537 1547

The SIFBITP tools for the assessment of passenger's behaviour in emergency situations

4 López-Pineiìv. EPérezA IC. Diaz C & VGonzále.zS

Improving formal safety assessment in shipping transportation

E. Mennic IN Lagoudis N Nikitakas &A Platis

Systematic analysis and review of AFRA.MAX tankers incidents

4. Papanikolaou E Eliopoulou A. Alicrafaki, S Ak.su, S. Delautre & N Mi/cells Risk-based approach to the design of passenger ro-ro ships regarding damaged stability TA. Santos & C: Gued Soares

Risk evaluation of life rafts in operation conditions

L S,nolarek

Assessment of partial safety factors for the longitudinal strength of tankers ₁₆₀₁ 4. P Teixeira & C. Guedes Soarer

Reliability based approach to determine the design loads for the remaining lifetime of ship hulls 1611 A.P Teixeira.. C Guedes Soares & G Wang

Energising safety management in ports ₁₆₂₁

VM Trbojevic

Risk ciiteria foi ports and ships ₁₆₂₉

VM 7}'bojevic

Fundamental concepts of risk-based ship design ₁₆₃₇ D Vas.ralos D Konoves.szs & L Guarin

The navigational width for a vessel going on the trajectory in shallow water under wind and wave 1645 YL. Vorobyov & M B Kosoy

Modification of the chart presented in ECDIS ₁₆₅₃

A. Weintrit

Presentation of safety contours on electronic navigational charts ₁₆₅₉ A Weintrit

Minimum reliability index of the weak points ofvariably curved beam elements under pure flexure 1667

X

WAn &H Li

Reliability analysis ofceniral compression of an imperfect strut with

initial geometrical deformations ₁₆₇₃

XWuWAn&ZLI

A benchmark study on response surface method ₁₆₇₉

X Zheng RK Das, L.. Mi & B. Leira

2 6 Deignfo the protection of the environment

Oil spills in coastal zones: environmental impacts and practical mitigating solutions

.15 Antunes de Carmo. IL Pinho & IR Vieira

Diesel oil degradation in sea water

C Bilgin&Eyonsel

SOS - integration of a seaway independent oil skimming system into an oil recovery vessel

G.E C/ausc MA Amro & S Kosleck

BaUasting with Fresh Water to be interchanged on the harbours RB. González A. Alvarez A Salamanca & B Alvarez

Evaluation of the emissions from the super eco-ship and the corresponding conventional ship X Minamj & T Kuno

xv

1555 1565 1573 1583 1593 1689 1697 1703 1713 1721

System integration fo safety and effective operation of the superEco-Ship 1729

M Numano, T Kano, H Kin'arhinw & T Taidmoto

Black sea water pollution .1733

M Pana yotova Y Garbatov & C Quedes Soarer

Water and air pollution caused by maritime activities 1737

M Panayotova. Y Garbatov & C Guedes Soares

Life cycle assessment of ships 1751

MA. Shama

Design optimisation and test of TREBAWA system an onboard treatment of ballast water 1759

P Zhou T Leigh.. F Asian & K Hesse

MaritimeTransportatiöñ andExploitation of Ocean and

Coastal Resources - Guedes Soares,

Garbatov & Fonseca (ads) 2005 Taylor & Francis Group, London, ISBN 0415390362

Preface

These two volumes present the proceedings from the 11th International Maritime Association of the

Meditesranean Congress held in Lisbon, Portugal, from 26 to 30 September 2005, under the theme Maritime Transportation and Exploitation ofOceanand Coastal Resources

The International Congress of International Maritime Association of the Mediterranean has nearly 27-year

history smce the first Congress of the International Mantune Association of East Mediterranean (IMAEM)

held in Istanbul in 1978 It isa voluntary organization that was initiallyestablishedin 1974 by institutions from six countries (Bulgaria, Egypt, Greece, italy, Yugoslavia and Turkey), and was progressively enlargedto other

countriesneighbouringthe Mediterranean

The IMAEM Congresses were held every 3 years:

Ist in Istanbul in 1978 2nd in Tiieste Italy in Ï981,

3Éd in Athens, Greece'in 1984, 4th in Varna, Bulgaria in 1987 5th in Athens, Greece in 1990

After the conference in Greece, the name of the association

_{was changed to InternatiOnal Maritime}

Association ofthe Mediterranean (IMAM) and it has continued being an association of academic and

profes-sional institutions that aim to contribute to the efficient, economic and safe operation of ships, offshoreand

coastal'structuresandport infrasftucthrsin order to promote the advancement oftheuseof the seas and coastal

watersfor a sustainable development ofthe societies.

The following Congresses were: 6th in Vaina, Bulgaria, in 1993 7th inDubrovnik, Croatia, in 1995 8th in Istanbul,Tuxkey, 1997 9th in Ischia, Italy, 2000 10th in Crete Greece, 2002 11th in Lisbon, Portugal, 2005

Ihe Congress is addressed to individuals from industr% research organizations, _{universities, government} agencies, certifying authoritiesas well asdesigners, operators andowners who contiibute.toimproved knowl-edge about the marine environment, ship and offshore design,, building and maintenance technology, maritime

transportation and port operation and explóitation, offshore oil and gas exploitation, nautical activities and marinas, fisheries and aquaculture, maritimesafety andprotection of thé environment

The Congress deals withaspectsof theoretical and experimental research, design, production, operation and

maintenance, including the economic impact of those activities. Most of the _{technological developments} addressing ships or other maritime infrastructures have impact in either the maritime transportation or the exploitationoftheresources of the sea, both livingandmineralresources, as:welFas therecreational andleisure possibilities that the seas provide to mankind

While previous Congresses were more concerned withships and maritime transportation, the_{presentone has} widened the scope by including various topics related with the exploitation of_{ocean and coastal resources an}

area that is believed tobecome increasingly more important

rhe books deal with various aspects concerning the designand fabricationof vessels foi_maritime trans-poltatton, namely hydrodynamics structures machinery and propulsion systems control systems vessel design, shipyard technology, maintenance and repair These volumes bring together an extenive selection of papers reflecting a number of fundamental areas of the exploitation of ocean and coastal resources Subjects

include the marme environment, fisheries and aquaculture maritime transportation_{and port operation coastal}

Finding the hull form for given seakeeping. characteristics

G.K. Kapsenberg

MARIN, Wageningen, the NetherlandÑ

ABSTRACT This paper presents a method to find a hull form that satisfies as good as possible a set of

seakeeping requirements. The method uses an initial hull form that is characterized by a set of polynomials

that define the beam on the waterline, the draft and the sectional area as a function of the length. The sectional

shape is then defined by a 2 parameter Lewis transform Limits can be supplied to the parameters describing

the hull form The hull form is changed by changing the driving parameters that define the polynomials The

seakeeping behaviour is calculated using a linear strip theory program. An optimization method is used to

find the hull' form that approaches the seakeeping requirements as good as possible.

The method is applied to the design of a frigate. The required seakeeping characteristics are vertical

accel-erations that are half those of the original design The intermediate steps are shown and' the final hull shape is

presented.

I

INTRODUCTION

Optimizing hull forms to achieve certain objectives

is now a well developed branch in science. In the

early days this. work was restricted to a number of

design variants that were tank-tested to have

mini-mum resistance or minimini-mum required power. Today

this type of optimization is usually carried out using

potential flow solvers; the geometry changes are

or-ganized by special software that controls the local

hull shape. An example of this work is the

optimiza-tion of the bulbous bow design (Hoekstra et al.

2003); in most cases the method is tuned to

optimi-zation in the advanced design stage where only

small changes are possible; nevertheless important

reductions of the wave making resistance are then

still possible. In the near future this type of

optimi-zation can be done using RANSE solvers instead of

potential flow solvers.

From the seakeeping point of view, these minor

modifications of the hull form are irrelevant the

seakeeping characteristics of the ship will hardly

change. Seakeeping behaviour is governed by the

overall hull form rather than local details. Apart of

this, relatively little is known about what makes a

ship a good sea keeper. Original work was carried

Out by Bales (1980); this was later extended 'by

Wal-den (1983). Bothauthors used aseries of strip theory

calculations and a choice of seakeeping

require-ments to develop a seakeeping index. This index was

then related to hull form parameters by regression

analysis. Systematic calculatiOns and experiments

were carried out (Blok et al. 1984); the good

quali-ties of the best hull form were allocated to the large

longitudinal separation between the centre of

buoy-ancy and the centre of floatatión of the waterline.

Lloyd (1988) presented results of calculations that

showed beneficial effects of wide beam 'and shallow

draft. The results from Blok et al. were later

ana-lyzed as resulting from maximizing the water plane'

area coefficient (Kapsenberg et al.

1998). Funny

enough this same publication came up with a design

with a very low water plane area coefficient as an

optimum fOr the given seakeeping requirements.

The method in this paper

is

comparable to

Lloyd's method (1988) The idea is to characterize

the hull in a limited number of parameters that fix

the seakeeping behaviour. Since 'good' seakeeping

characteristics are dependent on the tasks the ship

has to perform, general advice on what makes a

ships hull a good seakeeping one is replaced by

di-rect calculàtions with specific criteria. The

paramet-ric description of the hull form uses no a-priori

knowledge; the hull form generation process is

or-ganized such that also rather strange hull forms can

result. The idea behind this is to determine first what

is possible and then to restrict oneself to more 'ship

like shapes' and to détermine höw much of the good

seakeeping qualities are to be sacrificed. Such a

sec-ond stage is also the moment to realize that a linear

seakeeping prediction is quite limited and that also

considerations like emergence of the bow and

slam-ming on re-entry must be considered, This second

stage is not covered in this paper.

2 THE CONCEPT

The basis idea of this development was that

seakeep-ing characteristics. oía ship are determined by the

gross overall hull shape. This means that a rough

de-scription of the ship is sufficient, and that relatively

minor modifications can be made later (to improve

powering or manoeuvring characteristics) without

changing the seakeeping behaviour.. A second

start-ing point was the desire to know the required shape

regardless of all the other design constraints and

subjective criteria related to a 'good ship' or 'current

best practice'.

The choice was made to describe ship sections

with tWo parameter Lewis transform. This requires

only a description of the design waterline, the draft

and the sectional area as a function of the length to

have a full 3D description of the hull form. The

beam, draft an sectional area as a function of length

are each described by two 3.order polynomials; one

for the forward end and one for the aft end. These

polynomials are connected to a possible parallel mid

body.. This results in a set of 21. parameters for a

complete hull form definition and would thus result

in a 21 dimensional design space.

The original idea was that these 21 parameters

would be totally independent, but this proved to be

impossible. One of the additional constraints that

were put in, was to keep the displaced volume

con-stant. This results. in a strong interaction of the

pa-rameters describing the SAC. Next to this

it

ap-peared to be necessary to have some interaction

between the parameters controlling the polynomials

for the beam and draft to keep section shapes within

the limits imposed by the Lewis transforms. The

length between perpendiculars and the displaced

volume is kept constant throughoutthis optimization

process.

3 NOMENCLATURE

A [m2] B [m] [m]

T

[m]

H0 _[-1

NAA [-j

NAF[-]

o.

_[]

V

[mi]

Sectional area

Sectional beam at the waterline

Length between perpendiculars

Sectional draft

Half beam to draft ratio, H0 = B/(2 T)

Station number aft where constant pail

of sectional area curve begins

Station number forward where constant

part of sectional areacurve ends

Sectional area coefficient, a = A/(BT)

Displaced volume

4 HULL FORM DEFINITION

The program uses a mathematical 'hull form

descrip-tion based on polynomials describing the secdescrip-tional

beam, draft and area. These polynomials are defined

by the values at the outer ends (at St O and' I or St 19

and 20 respectively) and at the location of their

maximum value with a zero longitudinal derivative

The hull form can either have or not a parallel mid

body. Initial testing of the software and the hull

forms it produced showed that better shapes' were

obtained using a description by polynomials of the

local beam to draft ratio HO and the sectional area

coefficient o- rather than the local beam and draft.

The polynomials define values for the beam, draft

and area for each of the 20 stations, the shape of the

sections :i5 defined by Lewis transforms and this hull

form is transferred to the seakeeping program.

The seakeeping calculations require some

addi-tional data: the' longitudinal position of the centre of

gravity LcG. and the pitch inertia Iyy. The

assump-tion is made that LcG is always the same as LcB and

the radius of gyration for pitch is assumed to be 0.25

Lpp; this results inI =(O25L) pV.

The method gives a good approximation of

nor-mal hull forms; this is illustrated in Figure 1 which

shows the body plan of a standard frigate hull form

and the form described by the software using the

polynomials and' the Lewis forms Certainly the

mo-tion characteristics of the hull form are well

charac-terized by this approximate method.

Figure 1 Actual hull shape of the frigate(top) and approxima-tion using Lewis forms;

5 LEWIS TRANSFORMS

The 'hull form is defined by a 2 parameter conformal

semi-circle. This so-called Lewis-transform is

de-fined by:

z

nO

This formula transforms a circle in the Ç -plane

with polar coordinates into a ship-like section in the

Z -plane with Cartesian coordinates. The formula

describes ship-like sections reasonably well, but at

extreme values of the parameters re-entry forms can

result. Therefore the following limits to the

coeffi-cients were used:

0.04 <HO <50.0

For HO 1,

c_up

=1.11735+0.0370/HO

tTLOW = 0.5843 5 - 0.2882*H0

(2)

Figure 3

YZ plot of possible section shapes using Lewis

transforms. B/(2.T) = 1, 0.30< c_< 1.10.

Initiator

Other parameters that are changed; sign

is indicated in brackets

AO (+) AM (-) A19 (-) NAA (-) NAF (-)

Al (+) AM (-) A19 (-) NAA (-) NAF(-)

AM (+) Al (-)

A19 -)

NAA (+) NAF -)

A19₍₊

₅

AM (-)

A20 +) AM (-)

NAA (+)

A19 +)

NAF (+)

NAF (+)

Al -)

Al 9 -)

For HO> 1,

= 1.12435+0.0300*H0

with a maximum o,,, = 1.4

GLOW = 0.59565 - 0.2995/HO

(3)

This area where Lewis transforms of ship sections

is applicable is indicated in Figure 2; Figure 3

illus-trates that this allows a wide range of section shapes.

6 CHANGING THE HULL FORM

The basic idea was that the hull form could be

changed by changing any of the 21 parameters

inde-pendently. This proved to give undesirable hull

forms in the case that a value at one of the outer

ends was changed. Due to the choice of the 3rd order

polynomial this could resulted in extreme

'over-shoots' of the beam, draft or area curves. This

prob-lem was solved by creating a weak link between the

values of the parameters at the ends: if the value at

the ends is changed, the value of the same parameter

at the neighbouring section is also changed in the

same direction. The step size of this secondary

change is 60% of the step size of the primary

change. After including this, it appeared to be

possi-ble to change the hull form quite radically.

7 CONSTRAINTS

The constraints already listed are those imposed by

the

Lewis

transforms

and

those

imposed on

neighbouring sections

to

keep

reasonable

hull

shapes. Extreme values of the input parameters are

also supplied as a constraint on the design space.

Next to this it was decided to keep the length and

the displaced volume constant. This second

require-ment needs some attention because it is allowed to

change the Sectional Area Curve (SAC). If one of

the 7 parameters describing the SAC is changed, 4

other parameters are also changed according to

Ta-ble 2. The taTa-ble indicates (on the first line) that, if

the area at St O is increased, the area midships and at

St 19 is reduced, and that the parallel midbody is

shifted aft by reducing NAA and NAF. Changes are

made in an iterative procedure that converges to the

initial displaced volume.

0.01 0.1 10 100

H0 = BI(2.T)

Figure 2 Area (indicated in green) for Lewis transforms that

gives ship-like sections.

8 THE DESIGN SPACE

An initial investigation of the design space is

re-quired for the development of the optimization

tech-nique. Special care has to be taken if there are many

local extremes. Calculations were made changing

the beam-draft ratio and the sectional

_area

coeffi-cient midships. The result is shown in Figure 4. The

colour indicates the error calculated on the actual

vertical acceleration level and the

_{required level.}

The figure shows that the design

space

is very

smooth and that there are no local minima.

Figure 4 The design space illustrated by changing _{the beam} drafi ratio and the area coefficient mid ships. The colour indi-cates the level of the error fijnction for the design objective (minimum acceleration).

9 THE ERROR FUNCTION

The error function to minimize in the first

example

is the vertical acceleration

_{on 3 locations: St 0, 10}

and 20. The acceleration on the 3 locations is

mini-mized with equal weight; the actual error function is

calculated as the square root of the sum of the

squares of the error on each location.

As a second example the relative motion

at the

forward perpendicular is chosen as the error

func-tion.

10 THE OPTIMIZATION METHOD

The optimization method that is used

to minimize

the error function is based

on a successive local

search and steepest descend method.

The 'Local Search' routine changes each

of the

21 parameters individually, changes possible

de-pendent parameters, checks if the hull form is

feasi-ble (within constraints of Lewis forms)

_and

calcu-lates the seakeeping characteristics. If

_{one of the}

checks has a negative result, the variation is not

in-cluded. The parameter that gives the largest

reduc-tion of the error is then selected for the 'Descend'

step of the program.

The 'Descend' step finds the maximum

_reduction

that can be achieved by changing just

one parameter.

Regardless of the success of the 'Descend' step, the

program continues with a new 'Local Search'.

If the 'Local Search' routine is unable

_{to find an}

error that is smaller than the actual

_{error, the step}

size is decreased and a new 'Local Search' is carried

out. The reduction of the step size results in

_a

con-vergence criterion; in order to check for local

min-ima, a final check on the converged design is carried

out with an increasing step size.

This optimization method is not very advanced,

but it proved to be a robust method and suitable for

the present problem.

11

_{TI-lE SEAKEEPING PROGRAM}

The seakeeping program embedded in the software

is a strip theory program with forward speed

correc-tions as developed by DeIft University of

Technol-ogy (Gerritsma et al. 1967). This method has been

used for many years and gives surprisingly good

re-suits for many hull forms, an application for very

fast ships is presented by Blok (Blok

et al. 1984).

Such a method is extremely fast

_{on present day}

PC's, the performance is about 1000

_{calculations (1}

speed, I wave direction, 15 frequencies) for

_different

hull forms in 1 minute.

12 EXAMPLE MINIMUM VERTICAL

ACCELERATIONS

As an example an optimization is carried out for a

frigate. The starting point is

a hull form that has

been used in seakeeping optimization studies before

(Kapsenberg et al. 1998), see Figure 1 bottom. The

objective was to minimize the vertical

_{accelerations}

on 3 locations: St 0, 10 and 20 to the minimum (the

target was set at 0). The ship is sailing at a speed of

18 kts in a head sea characterized by

_{a JONS WAP}

spectrum with a peakedness parameter y = 3.3 and a

zero up-crossing period T2 = 7.5 s.

An optimum is achieved after 80 iteration

steps

which includes 2165 times a strip theory calculation.

The error reduces quite quickly in the first 15

steps;

Figure 9, the hull form changes and the

_error

reduc-tions are quite small after this point. The initial

steps

to reduce the draft forward. This intermediate result

is shown in Figure 5. The vertical accelération is

mostly reduced at St 20

(37%

relative to the value

for the starting point). For the locations St 10 and 0

this is 22% and

13%

respectively.

After 15 iterations much more of the hull form is

changed, see Figure 6.. The Sectional area CUrve is

much flatter resulting in a very high prismatic

coef-ficient. The beam is increased over the full length

-5

50 CN E 50 E CD o 10 15 20

and the draft is reduced. These dramatic changes iñ

the hull shape result in reductións of thé vertical

ac-öeleration that are 50%, 46% and 52% respectively

fOr st 0, 10 and 20.

If we consider the seakeeping characteristics in

more detail, it shows that the largest reduction is due

to a lower pitch motion. This is illustrated by the

plots of the RAO's, see Figure 10 and Figure ii.

O

i

0.5 0.5

_5.

-15

-10

Bodyplan 50 E rD o iO 15 20 o E

I-10 15 80 40 Iteration

Figure 6 Resulting hull form (in red) after 15 iterations for minimized vertical accelerations. Thebeam draft and SAC of the start-ing point is given in blue.

80 0. o O 10 CN

-5

IO 15 20 50 10 15 20 St 0 . o 0 5 iO 15 20 0 20 40 60 St Iteration

Figure5 Result after 7 iterations. The new hull form isindicated in red in the beam, draft and vertical acceleration plots; the hull... form of thestarting point is indicated in red. The body plan is that of the new hull form.

Bodyplan

E o E

I--5

50 CS' E o Figure 7

20/

E

;

N E 50 O 50 O 10 15 20 10 15 20

st

Final hull form for minimized vertical accelerations.

0.6

:::

Figure 9 Error as a fbnction of the iteration step.

Bodyplan

o

0 10 15

Iteration

13 EXAMPLE MINIMUM RELATIVE

MOTIONS

The same hull form as used in the previous

ex-ample has been chosen as a starting point. The

er-ror function chosen now is to minimize the relative

motions at the bow. In this case it appeared to be

possible to reduce the error with 39%. The final

hull form is shown in Figure 8. The hull form

shows a SAC (and Centre of Buoyancy) that is

shifted aft, while the beam of the waterline forward

is increased. This results in very hollow sections

forward and very wide sections aft. The resulting

-e

a

o 10 15 20 10 15 20 o w I a 10 15 20

z 0.5

o

o 20 40 60 80 Iteration Bodyplan 20 25 10 15 20 15 20 o 5 10

st

Figure 8 Final hull form for minimized relative motionsat the bow.

80 100 o 0 20 40 60 Iteration 1 0.5 w

RAU of the relative motion at the bow is compared

to the same for the starting hull form in Figure 12.

14 CONCLUSIONS

Whether or not the final result of the example

calculation is a practical hull form, is not the issue

of this paper. The idea is that the software shows in

rigorous and objective way the direction to

im-proved seakeeping of ships. Rather than very

gen-1.5

z

05

0

-540 0 0.5 1

15

0.10

o

0.05 a. 0.00

i MF I RAO e-- MF-fin RAO

4--MF-1 phase o--MF-fin phase

wave frequency (radis]

Figure 10 Heave RAO and phase angle of the hull form at the start of the optimization (MF-l) and at the end of the

procedure (MF-final).

i--- MF-1 RAO

e-- MF-fin RAO

.+--MF-1 phase e--MF-fin phase

180 o fin w -180 -270 o--360 180 90 OE -90 -18O

e

a--270 -360 -450 540

Figure II Pitch RAO and' phase angle of the hull form at the start of the optimization (MF-1) and at the end of the pro-cedure (MF-final).

eral trends that are pointed out by studies using

systematic series, this method uses the existing

hull form and some - user defined - room in the

design parameters to find a better hull shape. Next

to this the actual seakeeping requirements are

di-rectly used'. The final

hull

form is dependent on the

requirement that is used in the optimization.

Ex-amples are given showing the minimization of the

vertical accelerations and the minimization of the

relative motions at the bow. Both requirements

re-suit in different hull forms as illustrated in graphs

and by the values of the main hull form parameters

as given in Table 1. This table shows that

minimiz-ing the vertical accelerations is achieved by

shift-ing both centre of floatatión and centre of

buoy-ancy forward (keeping the separation the same),

lowering block and vertical prismatic coefficients

and increasing prismatic and water plane

coeffi-cients. These results are mainly in line with those

from Lloyd (1988).

Optimizing the ship towards reduced relative

motions at the bow is achieved by shifting both

centre of floatation and centre of buoyancy aft

(also reducing the separation between the two),

lowering block and water plane coefficients and

increasing the vertical prismatic prismatic coeffi

cient. Noted is that the values of the coefficients

are dominated by the choice to base them on the

maximum values of the relevant parameters.

A warning is given to the user: never fully trust

the results from computer programs. Even if the

code has been written free of bugs, there are

as-sumptions made in the theory; it is a model of the

real world, not the real world itself in this case it

must be realized that the 'heart' of the software is a

linear seakeeping program. The results must be

used as an indication of the directión in which to

change a hull form. It is quite obvious that the final

- Sta rtingpoint

-

Final hullform

Figure 12 Relative motion at the bow of the hull form at the start of the optimization and the result for the final hull

form.

0 0.5

i

1.5 O 0.5

i

1.5

hull forms that are presented in this paper with

their shallow draft will not be good seagoing ships;

for instance the hull will be prone to severe

slam-ming in rather low waves.

The main use of the method presented in this

paper is - as we see it - two fold: By doing an

op-timization with a large design space, one gets an

idea of the main features of a hull form that is

op-timized with respect to seakeeping only. These

re-sults can be used in an early design phase. The

second way of using the method is in the advanced

design phase when the freedom to changes the hull

form is limited. The method can then indicate the

most effective change in the hull form to further

improve seakeeping.

Table I Main hull form parameters of starting point and the two optimized hull forms. Coefficients are based on maxima for beam and-draft.

REFERENCES

Blok J.J. and Beukelman w., 1984, 'The

high speed displacement ship systematic series hull

forms

-

seakeeping

characteristics', SNAME

Transactions.

Bales N.K., 1980, 'Optimizing the

seakeep-ing performance of destroyer type hulls',

13th

Symposium on Naval Hydrodynamics, Tokyo.

Gerritsma

J.

and Beukelman W.,

1967,

'Analysis of the modified strip theory for the

cal-culation of ship motions and wave bending

mo-ments', Netherlañds Ship Research Centre TNO

Report No. 96 S.

Hoekstra M.. and Raven H.C., 2003, 'A

practical approach to constrained hydrodynamic

optimization of ships', Proceedings NAV 2003

conference, June, Palermo, Italy.

Jong B. de, 197-3-, 'Computation of the

hy-drodynamic coefficients of oscillating cylinders,

Netherlands Ship Research Centre TNO Report

No. 1-45 S.

Kapsenberg G.K. and Brouwer R., 1998,

Hydrodynamic development for a Frigate for the

21 century, Proceedings PRADS'98 conference,

The Hague.

Lloyd A.R.J.M., 1988, The effect of hull

form

and

size

on

seakeeping,

Proceedings

CADMO '88 conference, Southampton.

Walden D.A., 1983, 'Extension of the Bales

seakeeping

rank

factor

concept',

Proceedings

ATFC, Hoboken.

Parameter

starting

point

Min

accel

M-in

Relmo

Length

per-pendiculars

114.10

114.10

1-14.10

Maximum

beam

B,x

13.1-4

27.04

22.40

-Mximum

_Tx

4.30

3.87

3.57

Displacement

Displ --

3110

3088

3089

Longitudinal

centre of

buoyancy

(fwd of APP)

LcB

-/L

0.461,9 0.5108 0.3804

Longitudinal

centre of

floatation

(fwd of APP)

LcF

/Lpp 0.4211 0.4697 O3946

Block

coeffi-cient

cB 0.4822 0.2585 0.3390

Prismatic

co-efficient

Cp

0.6079

0.7935

05779

Vertical

prismatic

co-efficient

cip

0.5972

0.2974 0.6631

Water plane

coefficient

cwp

0.8075

0.8691 0.5113