Proceedings of the 21st International Towing Tank Conference, ITTC’96, Volume 1, September 15-21, 1996, Trondheim, Norway (summary)

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Volume 1

21st

INTERNATIONAL

TOWING TANK

CONFERENCE

Proceedings

Volume I

Trondheim, Norway

September 15-21,1996

N T N U © [ S M f f i

The Norwegian University Norwegian Marine Technology of Science and Technology Research Institute

Uboratorium voor Seheepshydromochanlca j Afchiof Mekefwsg 2, 2628 CD

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2Ist

INTERNATIONAL

TOWING TANK

CONFERENCE

Organizing Committee

Mr. Arnold K. Hansen

Norwegian Marine Technology Research Institute

Dr. Erling Huse

Norwegian Marine Technology Research Institute

Dr. Odd Faltinsen

The Norwegian University of Science and Technology

Sponsors

MARINTEK

Advanced Production and Loading A/S

Det norske Veritas Classifications AIS

Kvcerner Masa-Yards Inc.

Royal Norwegian Ministry of Foreign Affairs

Research Council of Norway

SINTEF

Editor

Dr. Erling Huse

Norwegian Marine Technology Research Institute

ITTCK

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P R E F A C E

On behalf cf MARINTEK and The Norwegian University of Science and Technology I take great pleasure in welcoming the 21st ITTC to Bergen and Trondheim. The Technical Committees and the organisers have akeady spent considerable effort in preparing the Proceedings and the Conference. It is now up to all of us to make it a fruitful arrangement, sociaUy as well as professionally.

Over the past few decades we have witnessed a general technological development that seems to be ever-accelerating. TTie tiuee years that have passed since the 20tii ITTC have been no exception in tius respect. Looking more specifically at the area of interest to tiie ITTC community we have for instance a development witiiin information technology that changes our lives and activities significantiy. Awareness of tiie necessity to protect the environment has an impact on ship design. Interest in high speed .ships is no longer limited to naval applications. They have become an important commercial market for tiie shipping and shipbuilding industry, and tiius also more important for tiie ITTC member organisations. In the offshore industry tiie development of oil fields in very deep waters poses new challenges to us regarding numerical hydrodynamics as well as model testing techniques.

Business-wise the rapid changes may represent ups and downs in the market that can be hard to predict. An overall conclusion is tiiat in order to survive our member organisations must be flexible and capable of quick response to changes in tiie industry. In tiiis situation it is important tiiat tiie ITTC be an efficient tool for the member organisations, and not an obstacle to rapid technological changes. Considering tiie present interest in ITTC shown by tiie member organisations it is my sincere belief tiiat we shall manage to maintain and augment tiie role of ITTC as tiie efficient tool we want it to be.

The 21st ITTC is deviating somewhat from traditional arrangements in tiie sense that it takes place partly on board a ship. We hope tiiat you will find titis arrangement, togetiier witii tiie technical and social programs interesting, and tiiat your visit to Norway will be a rewarding and memorable one.

Managing Director, MARINTEK Chair, Executive Committee, 21st ITTC

L 1996 J

Table of Contents

Proceedings ofthe 21'' ITTC

Volume 1

Preface i Committees of the 21st ITTC I

Report of the Advisory Council 3 1 Membership and Meetings 3 2 Activities and Recommendations of the Advisory Council 3

3 Officers for tiie 22nd Advisory Council 5

Report of the Executive Committee 7

1 Introduction 7 2 Obituaries 7 3 Committee Membership 9

4 Committee Meetings 9 5 Committee Decisions 9 Report of the Seakeeping Committee 11

1 Membership and Meetings 11 2 Recommendations of the 20th ITTC 11

3 Wave Generation and Beach Characteristics in Experimental Facilities 12

4 Numerical Predictions of Forces and Motions . . . .' 13

5 Seakeeping in Extreme Weather Conditions 17

6 Nonlinear Rolling and Capsizing 22 7 Experimental and Testing Techniques for Seakeeping for HSMVs 27

8 Seakeeping Performance of Twin Hull Configurations 30 9 Full Scale Measurements and Real Time Forecasting 32

10 Seakeeping Assessment 34 11 Uncertainty Analysis and Validation Procedures 36

12 Conclusions and Recommendations 43

13 References 44 Report of the Cavitation Committee 63

1 Membership and Meetings 63 2 Recommendations of the 20th ITTC 64

3 Introduction 64 4 Measurements of Hull Pressure Fluctuation 65

5 Cloud Cavitation 72 6 Mechanism, Scale Effects, and Delay of Vortex Cavitation 80

" 7 Computational Efforts to Predict Cavitation 92 8 Cavitation Nuclei Effects on Inception 95 9 High-speed Cavitation Peifomiance 105

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10 Blade Cavitation Pattems 109

11 Quality Control 113 12 Conclusions to the Conference 117

13 Recommendations to the Conference 117

References 117 Report of the Propulsor Committee 127

1 General 127 2 Comparative Experiments on Steady State Reynolds Number Effects 128

* 3 Evaluation of Experimental and Theoretical Prediction Techniques for Unconventional Methods of Propulsion such as Tip Plate,

Ring and Ducted Propellers 129 4 Provide Advice on Boundary Layer Tripping on Propulsor Siufaces

that exhibit Significant Viscous Effects in Model Wake 143

5 Propulsor Literature Database 145 6 Guide for the use of LDV for the Collection of Propulsor Data Suitable for

Validation of Numerical Calculations 147 7 High Speed Propulsor and Interaction Effects for High Speed Marine Vehicles . . . . 153

• 8 Developments in the use of Panel Methods and RANS Equation Codes for PropulsorsI59

9 Reynolds Number Dependency of Lift Coefficient for Wing Sections 170

10 Standard Procedures and Codes Conforming to ISO 9000 174

11 Conclusions 176 12 Recommendations to the Conference 177

13 References 177 Report of the Waterjets Group 189

1 General 189 2 Literature Survey 190

3 Discussion of Possible Power Prediction Methods for

Watcrjet Propulsion System ..." 191 4 Recommendations to tiie Conference 198

5 References 198 Appendix A Possible Power Preciction Metiiod for Waterjet systems 200

Appendbc B Proposed List of ITTC Symbols for Waterjets 204

Appendix C Direct Thrust Measurement Method 205

Appendix D Sensitivity Aspect 208 Report ofthe Performance in Ice-Covered Waters Committee 211

1 General 211 2 Standard Test Methods for Model Ice Properties 212

3 Recommended Procedures for Ice Model Tests 222

4 Recommendations for Ship Trials in Ice 239

5 Analysis of tfie Cylinder Tests 245 6 Model Propulsion Tests in Ice 252 7 BibUography of Ships in Ice 1993 - 1995 263

8 References 269 9 Recommendations to the Conference 270

Report of the Ocean Engineering Committee 271

1 General 271 2 Survey of Existing Test Techniques and Procedures 272

3 Exttapolation Technique for full Scale Low-Frequency Damping Characteristics

of Model Tests 276 4 Recommended Test Procedures 281

5 Review on Numerical Models for Time-Domain Simulation of

Slow-oscillating Motions of Offshore Structures 283 6 Short-crested Wave Experimental Techniques 289 7 Combination of Exffeme Wind, Wave and Current Parameters 292

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» 9 Validation of the Mean Wave Drift Forces using the Nearfield and Farfield Methods 299

10 Short Review of Ocean Engineering Research of Interest to the ITTC 303

11 Conclusions and Recommendations 305

References 307

Report of the Quality Control Group 315

1 General 315 2 Activities of 2 IstlTTCQCG 315

3 Report of Technical Committees ' Work on Quality Control Activities 322

4 ISO Certification Process 324 5 ISO Certifiation - tiie Current Trend 325

6 Conclusions 326 7 Recommendations to the Conference 326

8 References 327 Appendix A: Example: Current Marin Quality Assurance System Document 327

Appendix B: Sample DTMB ISO 9000 Procedure 329 Appendix C: Sample DTMB ISO 9000 Work Instruction 333

Report of the Symbols and Terminology Group 339

1 General 339 2 Work of the Group 340

3 Conclusions 346 4 Recommendations to the Conference , , 346

Report of the Manoeuvrability Committee 347 1 General ' ' 347

2 Special Groups ' 348

3 Prediction of Forces 349 4 Simulation of Dynamics : 356 5 Non-conventional Craft 36\ 6 Validation, Scale Effects and Full Scale Trials 36%

7 Ship Operation & Safety, IMO Standards 371 8 Evolution of Model Testing Methods 377 9 Recommended Standard PMM Test Procedure 378

10 Conclusions of the Committee 381

11 Referances 382 Report of the Powering Performance Committee 3S»9

1 Membership and Meetings 399 2 Recommendations of the 20th ITTC 399

3 Introduction . '. 400 4 Standard Method for Analysis of Full Scale Trial Results . . . AQ\ 5 Standardize Uncertainty Analysis for Representative Testing Metiiods

for Powering Predictions 411 6 Conformance to ISO 9000 416 7 Self-propulsion Test Methods for Separation-prone Hull Foirns . . . 418

8 Reynolds Nimiber Dependency of Form Factor A\9

9 Powering Predictions for Ships Fitted with Conu-arotating Propellers and

Propellers with Stators 423 10 Conclusion . . . ] . . . . [ [ 430

11 Recommendations to the Conference 431

12 Acknowledgments 431 Appendix I - An Updated Guide for Speed/Powering Trials 431

Appendix n - Propulsion Test Metiiods 434 13 References " ' ' 435

IV

Report of the Resistance and Flow Committee 439

1 Introduction 439 2 A Naval Architect's view 441

3 General Trends in Computational Fluid Dynamics 451

4 CFD Uncertainty Analysis 464 5 A User's Guide Standard for CFD Application 482

6 CFD as an Assistant to Model Experiments 487 7 Conclusions

8 Recommendations to the Conference 500 References

Report ofthe High-Speed Marine Vehicles Committee 515

1 General 515 2 Review of Research in HSMV safety of hiterest to tiie ITTC 5 lö

3 Conclusions and Recommendations 542

4 References 544 Appendices

1. The Rules of the Organization 1. Aims 2. Activities 3. Membership ^^J 4. Organisation 5. Groups ^^T 6. Meetings - • • ••• irz

7. Compositionof Executive Committee based on Geographic Areas

8. List of Geographic Areas r ^ ^ ^ l ^ t

9. General Additional Guidelines for tiie operation of tiie ITTC • ^oz> 2. New Technical Committee Structure

1 Structure of tiie Technical Committees J^/ 2 Terms of Reference of General and Specialist Committees /

3 Mechanism for Identifying New Specialist Technical Committees ^o»

4 Tasks of Speciahst Committees of 22°" r i T C 56K

3. Index of m C Documents ^'^ 1. ITTC Organisation 2. Proceedings 3. ITTC Publications ™ 4 ITTC Addresses ^ " 579 4. Member Organisations

5. Delegates invited to the 21" TTTC ^^"^ 6. Guidelines for Preparation of Technical Committee and Working Group Reports . . 595

1. Overview 2. Materials 3. Page Geometry 4. Text 597 5. Matiiematics ^g-j 6. Graphic material ' 1. References