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Dnv-Rp-H103 Modelling and Analysis of Marine Operations

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Dnv-Rp-H103 Modelling and Analysis of Marine Operations RECOMMENDED PRACTICE DNV-RP-H103 MODELLING AND ANALYSIS OF MARINE OPERATIONS APRIL 2010 DET NORSKE VERITAS FOREWORD DET NORSKE VERITAS (DNV) is an autonomous and independent foundation with the objectives of safeguarding life, prop- erty and the environment, at sea and onshore. DNV undertakes classification, certification, and other verification and consultancy services relating to quality of ships, offshore units and installations, and onshore industries worldwide, and carries out research in relation to these functions. DNV Offshore Codes consist of a three level hierarchy of documents: — Offshore Service Specifications. Provide principles and procedures of DNV classification, certification, verification and con- sultancy services. — Offshore Standards. Provide technical provisions and acceptance criteria for general use by the offshore industry as well as the technical basis for DNV offshore services. — Recommended Practices. Provide proven technology and sound engineering practice as well as guidance for the higher level Offshore Service Specifications and Offshore Standards. DNV Offshore Codes are offered within the following areas: A) Qualification, Quality and Safety Methodology B) Materials Technology C) Structures D) Systems E) Special Facilities F) Pipelines and Risers G) Asset Operation H) Marine Operations J) Cleaner Energy O) Subsea Systems Amendments and Corrections This document is valid until superseded by a new revision. Minor amendments and corrections will be published in a separate document normally updated twice per year (April and October). For a complete listing of the changes, see the “Amendments and Corrections” document located at: http://webshop.dnv.com/global/. The electronic web-versions of the DNV Offshore Codes will be regularly updated to include these amendments and corrections. Comments may be sent by e-mail to [email protected] For subscription orders or information about subscription terms, please use [email protected] Comprehensive information about DNV services, research and publications can be found at http://www.dnv.com, or can be obtained from DNV, Veritas- veien 1, NO-1322 Høvik, Norway; Tel +47 67 57 99 00, Fax +47 67 57 99 11. © Det Norske Veritas. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, including pho- tocopying and recording, without the prior written consent of Det Norske Veritas. Computer Typesetting (Adobe FrameMaker) by Det Norske Veritas. Printed in Norway. If any person suffers loss or damage which is proved to have been caused by any negligent act or omission of Det Norske Veritas, then Det Norske Veritas shall pay compensation to such person for his proved direct loss or damage. However, the compensation shall not exceed an amount equal to ten times the fee charged for the service in question, provided that the maximum compen- sation shall never exceed USD 2 million. In this provision "Det Norske Veritas" shall mean the Foundation Det Norske Veritas as well as all its subsidiaries, directors, officers, employees, agents and any other acting on behalf of Det Norske Veritas. Recommended Practice DNV-RP-H103, April 2010 Changes – Page 3 MAIN CHANGES The main changes include a new Section 9 on Lifting Opera- tions covering heavy lift operations where motion of lifted object may influence the motion of the crane vessel. The new chapter also include guidance on hydrodynamic coupling between vessels situated close to each other and the topic of probability of barge hitting lifted object when lifting an object onto a barge in waves. In Section 5 on Deepwater Lifting Oper- ations guidance is given on slack cable conditions and general properties of fibre ropes for use in deepwater lifting. DET NORSKE VERITAS Recommended Practice DNV-RP-H103, April 2010 Page 4 – Changes DET NORSKE VERITAS Recommended Practice DNV-RP-H103, April 2010 Contents – Page 5 CONTENTS 1. GENERAL .............................................................. 7 3.3.5 Drag coefficients for circular cylinders ............................ 26 3.3.6 Estimating added mass and damping coefficients 1.1 Introduction .............................................................7 from model tests or CFD analyses.................................... 27 1.2 Objective...................................................................7 3.4 Calculation methods for estimation 1.3 Relationship to other codes.....................................7 of hydrodynamic forces ........................................27 1.4 References ................................................................7 3.4.1 The Simplified Method..................................................... 27 3.4.2 Regular design wave approach......................................... 28 1.5 Abbreviations...........................................................7 3.4.3 Time domain analyses ...................................................... 30 1.6 Symbols.....................................................................7 3.4.4 CFD analyses.................................................................... 30 1.6.1 Latin symbols......................................................................7 3.5 Moonpool operations ............................................31 1.6.2 Greek symbols ....................................................................9 3.5.1 General ............................................................................. 31 3.5.2 Simplified analysis of lift through moonpool................... 31 2. GENERAL METHODS OF ANALYSIS ............. 9 3.5.3 Equation of motion ........................................................... 31 2.1 Introduction .............................................................9 3.5.4 Resonance period.............................................................. 32 3.5.5 Damping of water motion in moonpool ........................... 32 2.2 Description of waves................................................9 3.5.6 Force coefficients in moonpool ........................................ 34 2.2.1 General................................................................................9 3.5.7 Comprehensive calculation method.................................. 34 2.2.2 Regular waves...................................................................10 3.6 Stability of lifting operations................................35 2.2.3 Modelling of irregular waves............................................10 2.2.4 Breaking wave limit..........................................................10 3.6.1 Introduction ...................................................................... 35 2.2.5 Short term wave conditions ..............................................11 3.6.2 Partly air-filled objects ..................................................... 35 3.6.3 Effects of free water surface inside the object.................. 35 2.2.6 Pierson-Moskowitz and JONSWAP spectra ....................11 2.2.7 Directional distribution of wind sea and swell .................12 3.7 References..............................................................35 2.2.8 Maximum wave height in a stationary sea state ...............12 4. LIFTING THROUGH WAVE ZONE – 2.3 Wave loads on large volume structures...............12 SIMPLIFIED METHOD..................................... 35 2.3.1 Introduction.......................................................................12 2.3.2 Motion time scales............................................................12 4.1 Introduction...........................................................35 2.3.3 Natural periods..................................................................13 4.1.1 Objective........................................................................... 35 2.3.4 Frequency domain analysis...............................................13 4.1.2 Application ....................................................................... 35 2.3.5 Multi-body hydrodynamic interaction..............................14 4.1.3 Main assumptions............................................................. 36 2.3.6 Time domain analysis.......................................................15 4.2 Static weight...........................................................36 2.3.7 Numerical methods...........................................................15 4.2.1 General.............................................................................. 36 2.3.8 Frequency and panel mesh requirements..........................15 4.2.2 Minimum and Maximum Static weight............................ 36 2.3.9 Irregular frequencies.........................................................16 4.3 Hydrodynamic forces............................................36 2.4 Wave Loads on small volume structures.............16 4.3.1 General.............................................................................. 36 2.4.1 Small volume 3D objects..................................................16 4.3.2 Wave periods .................................................................... 36 2.4.2 Sectional force on slender structures ................................16 4.3.3 Crane tip motions.............................................................. 37 2.4.3 Definition of force coefficients.........................................17 4.3.4 Wave kinematics............................................................... 37 2.4.4 Moving structure in still water..........................................17 4.3.5 Slamming impact force....................................................
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