COER verification of simulation of Floating Bodies

Transcription

1 Marine Renewables Infrastructure Network Infrastructure Access Report Infrastructure: UNI-STRATH Kelvin Hydrodynamics Laboratory User-Project: COERverFB COER verification of simulation of Floating Bodies Center for Ocean Energy Research NUI Maynooth Status: Draft Version: 01 Date: 07-Nov-2013 EC FP7 Capacities Specific Programme Research Infrastructure Action

2 ABOUT MARINET MARINET (Marine Renewables Infrastructure Network for emerging Energy Technologies) is an EC-funded network of research centres and organisations that are working together to accelerate the development of marine renewable energy - wave, tidal & offshore-wind. The initiative is funded through the EC's Seventh Framework Programme (FP7) and runs for four years until The network of 29 partners with 42 specialist marine research facilities is spread across 11 EU countries and 1 International Cooperation Partner Country (Brazil). MARINET offers periods of free-of-charge access to test facilities at a range of world-class research centres. Companies and research groups can avail of this Transnational Access (TA) to test devices at any scale in areas such as wave energy, tidal energy, offshore-winareas such as power take-off systems, grid integration, materials or moorings. In total, over 700 weeks of access is energy and environmental data or to conduct tests on cross-cutting available to an estimated 300 projects and 800 external users, with at least four calls for access applications over the 4-year initiative. MARINET partners are also working to implement common standards for testing in order to streamline the development process, conducting research to improve testing capabilities across the network, providing training at various facilities in the network in orderr to enhance personnel expertise and organisingg industry networking events in order to facilitate partnerships and knowledge exchange. The aimof the initiative isto streamline the capabilities of test infrastructures in order to enhance their impact and accelerate the commercialisation of marine renewable energy. See for more details. Partners Ireland University College Cork, HMRC (UCC_HMRC) Coordinator Sustainable Energy Authority of Ireland (SEAI_OEDU) InstitutFrançais de Recherche Denmark Aalborg Universitet (AAU) DanmarksTekniskeUniversitet (RISOE) France Ecole Centrale de Nantes (ECN) Pour l'exploitation de la Mer (IFREMER) United Kingdom National Renewable Energy Centre Ltd. (NAREC) The University of Exeter (UNEXE) European Marine Energy Centre Ltd. (EMEC) University of Strathclyde (UNI_STRATH) The University of Edinburgh (UEDIN) Queen s University Belfast (QUB) Plymouth University(PU) Spain Ente Vasco de la Energía (EVE) Tecnalia Research & Innovation Foundation (TECNALIA) Belgium 1-Tech (1_TECH) Netherlands Stichting Tidal Testing Centre (TTC) StichtingEnergieonderzoek Centrum Nederland (ECNeth) Germany Fraunhofer-GesellschaftZurFoerderung Der AngewandtenForschung E.V (Fh_IWES) Gottfried Wilhelm Leibniz Universität Hannover (LUH) Universitaet Stuttgart (USTUTT) Portugal Wave Energy Centre Centro de Energia das Ondas (WavEC) Italy Universitàdegli Studi di Firenze (UNIFI-CRIACIV) Universitàdegli Studi di Firenze (UNIFI-PIN) Università degli Studi della Tuscia (UNI_TUS) Consiglio Nazionale delle Ricerche (CNR-INSEAN) Brazil Instituto de Pesquisas Tecnológicas do Estado de São Paulo S.A. (IPT) Norway SintefEnergi AS (SINTEF) NorgesTeknisk-NaturvitenskapeligeUniversitet (NTNU) Page 2 of 26

3 DOCUMENT INFORMATION Title COER verification of simulation of Floating Bodies Distribution Public Document Reference MARINET-TA1- COERverFB User-Group Leader, Lead Ronan Costello Centre for Ocean Energy Research, NUI Maynooth Author Centre for Ocean Energy Research National University of Ireland Maynooth User-Group Members, Contributing Authors DavidePadeletti Centre for Ocean Energy Research, NUI Maynooth Infrastructure Accessed: UNI-STRATH Kelvin Hydrodynamics Laboratory Infrastructure Manager Charles Keay (or Main Contact) REVISION HISTORY Rev. Date Description Prepared by (Name) Approved By Infrastructure Manager Status (Draft/Final) First report version DavidePadeletti Draft Page 3 of 26

4 ABOUT THIS REPORT One of the requirements of the EC in enabling a user group to benefit from free-of-charge access to an infrastructure is that the user group must be entitled to disseminate the foreground (information and results) that they have generated under the project in order to progress the state-of-the-art of the sector. Notwithstanding this, the EC also state that dissemination activities shall be compatible with the protection of intellectual property rights, confidentiality obligations and the legitimate interests of the owner(s) of the foreground. The aim of this report is therefore to meet the first requirement of publicly disseminating the knowledge generated through this MARINET infrastructure access project in an accessible format in order to: progress the state-of-the-art publicise resulting progress made for the technology/industry provide evidence of progress made along the Structured Development Plan provide due diligence material for potential future investment and financing share lessons learned avoid potential future replication by others provide opportunities for future collaboration etc. In some cases, the user group may wish to protect some of this information which they deem commercially sensitive, and so may choose to present results in a normalised (non-dimensional) format or withhold certain design data this is acceptable and allowed for in the second requirement outlined above. ACKNOWLEDGEMENT The work described in this publication has received support from MARINET, a European Community - Research Infrastructure Action under the FP7 Capacities Specific Programme. LEGAL DISCLAIMER The views expressed, and responsibility for the content of this publication, lie solely with the authors. The European Commission is not liable for any use that may be made of the information contained herein.this work may rely on data from sources external to the MARINET project Consortium. Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data. The information in this document is provided as is and no guarantee or warranty is given that the information is fit for any particular purpose. The user thereof uses the information at its sole risk and neither the European Commission nor any member of the MARINET Consortium is liable for any use that may be made of the information Page 4 of 26

5 EXECUTIVE SUMMARY The Centre for Ocean Energy Research (COER) at NUI Maynooth has developed expertise in control, numerical hydrodynamic analysis and in numerical optimisation of wave energy devices. We have several ongoing projects that are building on this background and in different ways develop and/or exploit numerical models of wave energy devices. The TEOWEC project aims to develop integrated techno-economic optimisation software for wave energy converters. The technical part of this techno-economic analysis and optimisation is composed of frequency and time domain analysis of the wave energy converter. The purpose of this MARINET project is to generate experimental data that will support validation and extension of these numerical models. This was done successfully by measuring the response of a generic floating body with moorings to incoming waves. The response was measured with 3d optical motion capture and with wave gauges. The measured response and the predicted response were in very good agreement. The work reported in this document has also been reported in the following publication: Costello, R., Padeletti, D. and Ringwood, J.V.. "Comparison of Numerical Simulations with Experimental Measurements for the Response of a Modified Submerged Horizontal Cylinder Moored in Waves." Proc. OMAE, San Francisco, Available online at: Figure 1-1: Our model of a generic floating body. Page 5 of 26

6 CONTENTS 1 INTRODUCTION& BACKGROUND INTRODUCTION DEVELOPMENT SO FAR Stage Gate Progress Plan For This Access OUTLINE OF WORK CARRIED OUT MODEL CHARACTERISTICS BASIN SETUP TESTS Test Plan RESULTS Free Decay Tests Monochromatic Wave Tests Panchromatic Wave Tests ANALYSIS &CONCLUSIONS MAIN LEARNING OUTCOMES PROGRESS MADE PROGRESS MADE: FOR MARINE RENEWABLE ENERGY INDUSTRY FURTHER INFORMATION SCIENTIFIC PUBLICATIONS WEBSITE &SOCIAL MEDIA APPENDICES Page 6 of 26

7 1 INTRODUCTION& BACKGROUND 1.1 INTRODUCTION The Centre for Ocean Energy Research (COER) at NUI Maynooth has developed expertise in control, numerical hydrodynamic analysis and in numerical optimisation of wave energy devices. We have several ongoing projects that are building on this background and in different ways develop and/or exploit numerical models of wave energy devices. The purpose of this MARINET project is to generate experimental data that will support validation and extension of these numerical models. TEOWEC is a WEC device optimisation project which runs from 2012 to The TEOWEC project uses frequency and time domain calculations to quantify the power production of candidate WEC devices. These calculations rely on hydrodynamic coefficients produced by linear radiation-diffraction solvers and as such require special attention to include the viscous forces on the floating bodies. We would like to generate experimental data so that these viscous terms can be identified for inclusion in these calculations. To facilitate commercially relevant numerical design optimisation in wave energy conversion accurate and validated simulations of wave body interactions are necessary. Wave energy, more so than almost any other industry, can benefit from such numerical optimisation because of the high cost and long design iteration times of experimental and field testing. For the foreseeable future wave energy device design and optimisation will continue to rely heavily on potential flow solvers. Two important prerequisites to successfully using simulations based on these codes are firstly a need to validate the simulation implementation by comparison with experiment and secondly a need to supplement the potential flow solution with experimentally (or CFD) derived coefficients for the forces that are neglected by the potential flow solver. This work in part addresses both of these prerequisites. A comparison of numerical simulations and physical wave tank experiments on a submerged horizontal cylinder moored in waves is facilitated by the measurements made. The shape of the wetted surface is generic; it is neither a ship nor any particular wave energy device. A horizontal cylinder is chosen because it is a generic shape that is thought to be more relevant to wave energy conversion devices than other generic shapes (such as, for example, a vertical cylinder). The submerged cylinder is augmented to give it a surface piercing element so that a heave resonance occurs. The moorings of the submerged cylinder are vertical lines with a clump mass arranged so that a resonance also occurs in surge. Results from two configurations are reported, the first has the heave and surge resonance frequencies well outside the frequency range of the tests, while the second has these resonances within the frequency range of the test. For each of these configurations a series of free decay tests in heave and surge were undertaken followed by a series of monochromatic waves and pan chromatic sea states. The first of these configurations gives results with mild motion that are predicted very well by the results of numerical models based on potential flow theory, thereby validating our implementation. The second of these configurations gives results with more vigorous response and larger motion amplitudes, in turn leading to significant shearing and vortex shedding forces. This second set of results allows extraction of coefficients for forces not included in potential flow solutions. Page 7 of 26

8 1.2 DEVELOPMENT SO FAR This project was targeted at generating experimental measurements of the response of a generic shape to waves and not to a particular wave energy device. As such the stage gate and technology readiness levels do not apply directly. The intention is to make data recorded in this project available under an open data arrangement so that others may benefit from this as well. The stage gate table below is filled out to indicate the general usefulness of the data generated rather than the applicability to any particular device Stage Gate Progress Previously completed: Planned for this project: STAGE GATE CRITERIA Stage 1 Concept Validation Linear monochromatic waves to validate or calibrate numericalmodels of the system ( waves) Finite monochromatic waves to include higher order effects ( waves) Hull(s) sea worthiness in real seas (scaled duration at 3 hours) Provide the empirical hydrodynamic co-efficient associated withthe device (for mathematical modelling tuning) Investigate physical process governing device response. May notbe well defined theoretically or numerically solvable Evidence of the device seaworthiness Status Plan For This Access The work took place the Kelvin Hydrodynamics laboratory in Strathclyde University over a two week period. The testing was split into two model configurations, one tested in each week of the access. The first model configuration was designed to avoid resonances in the rigid body modes in the frequency ranges tested while the second configuration was designed to have resonances in heave and surge that occur at frequencies in the range tested. Week 1: Outline plan. Day am/pm Config Test type H T Mon am Cyl cfg. A Setup Mon pm Cyl cfg. A Free decay, heave and surge. Several repeat tests. Tue am Cyl cfg. A Mono H=0.05m 16 periods 0.7 to 4.0s. Tue pm Cyl cfg. A Mono H=0.10m 16 periods 0.7 to 4.0s. Wed am Cyl cfg. A Mono H=0.15m 16 periods 0.7 to 4.0s. Wed pm Cyl cfg. A Pan Hs= peak periods 0.7 to 4.0s. Thurs am Cyl cfg. A Pan Hs=0.10m 16 peak periods 0.7 to 4.0s. Thurs pm Cyl cfg. A Pan Hs=0.15m 16 peak periods 0.7 to 4.0s. Fri am am Repeat/re-work as necessary. Fri pm pm Repeat/re-work as necessary. Page 8 of 26

9 Week 2: Outline plan. Day am/pm Config Test type H T Mon am Cyl cfg. B Setup Mon pm Cyl cfg. B Free decay, heave and surge. Several repeat tests. Tue am Cyl cfg. B Mono H=0.05m 16 periods 0.7 to 4.0s. Tue pm Cyl cfg. B Mono H=0.10m 16 periods 0.7 to 4.0s. Wed am Cyl cfg. B Mono H=0.15m 16 periods 0.7 to 4.0s. Wed pm Cyl cfg. B Pan Hs= peak periods 0.7 to 4.0s. Thurs am Cyl cfg. B Pan Hs=0.10m 16 peak periods 0.7 to 4.0s. Thurs pm Cyl cfg. B Pan Hs=0.15m 16 peak periods 0.7 to 4.0s. Fri am am Repeat/re-work as necessary. Fri pm pm Repeat/re-work as necessary. 2 OUTLINE OF WORK CARRIED OUT 2.1 MODEL CHARACTERISTICS The geometry selected for testing is a submerged cylinder with hemispherical caps and two rectangular columns protruding vertically from the cylinder through the water surface. The two water piercing columns gave the model a hydrostatic stiffness and so a resonance in heave. The shape of the modified cylinder is shown in Figure 2. Figure 2: CAD model of the modified cylinder shape. The mooring arrangement was composed of vertical lines that ran from the cylinder to a deeply submerged clump mass and horizontal lines from the clump mass to the tank walls. The front lines (towards the wavemaker) were fixed length lines so that the clump mass moved in an arc about the axis through the attachment points of the front lines at the tank walls. These lines were long compared to the range of motion so the arc of motion of the mooring lines was very small and the motion of the clump mass was very close to perfectly vertical. The rear lines (away from the wavemaker) were arranged to be constant tension rather than constant length, with a minimum tension necessary to keep the front lines from becoming slack. The surge stiffness of the cylinder is related to the mass of the clump mass. By transferring mass between the cylinder and the clump mass the surge resonant frequency could be tailored to suit the objectives of the project. Page 9 of 26

10 Two different configurations were tested, each with different column sizes and so different heave resonant frequencies and different clump mass so different surge frequencies. Figure 3End view of mooring arrangement. The dimensions and mass characteristics of the two model configurations are summarised on Table I. Table 1: Dimensions and mass properties of two configurations. Configuration I composed small rectangular columns, small clump mass very low resonant frequencies in both heave and surge, well below the test frequency range. Configuration II composed larger rectangular columns, larger clump mass, stiffer system in both heave and surge than cfg I, heave and surge resonances in the test frequency range. Page 10 of 26

11 Figure 4 Cylinder and clump mass. Configuration B Page 11 of 26

12 2.2 BASIN SETUP A schematic representation of the basin is shown in Figure 5. The model and theclump mass were connected together by rigid vertical lines so that the cylinder was submerged with only the rectangular columns piercing the water surface. The device was then placed in the centre of the tank, with 3 moorings (one back and 2 front) fixing the counter mass. The front moorings were rigid fixed length steel lines. The rear mooring was rigid steel line run over pulleys to suspend a 5kg weight (above water), this gave a variable length line with close to constant tension. This arrangement gave the desired behaviour of close to vertical motion and negligible horizontal motion of the clump mass. To measure the free surface elevation we used a fixed probe and 2 inline probes. A six camera motion tracking system was used in order to measure the position of a marker array (4 spherical reflectors) placed on the top of the body model. A fully submerged camera recorded each run. The requirements for the experimental tests are a wave test tank with the ability to undertake a series of free decay and forced oscillation tests of a range of wetted shapes. COER does not have the facilities in-house to do this nor does the facility exist elsewhere in Ireland, the Strathclyde tank is well suited to the proposed tests. Figure 5 -Schematic representation of the basin setup. Page 12 of 26

13 2.3 TESTS Test Plan The testing was conducted over two weeks at the Kelvin Hydrodynamics Laboratory, University of Strathclyde. Three different type of experiments for the two hardware configurations were conducted : 1. Free Decay tests, for both heave and surge 2. Monochromatic wave tests for three different wave amplitudes : 12.5, 25 and 75 mm 3. Panchromatic wave tests with incresing Sea State values going from 1.1 to 3.3, incremented by 0.2 The Table below provides information about the test plan. In each run the amplitude, frequency and phase were obtained by fitting the time series numeric values over a steady state interval of normally 20-30s. Video records were taken for each experiment and saved using the same dataset file number. In the next section some plots showing the main results are briefly presented. Video records were taken for each experiment and saved using the same dataset file number. Page 13 of 26

14 Cfg I I I I I I I wave mono mono mono mono mono mono(rep) mono T [s] 0,90 1,10 1,30 1,50 1,70 1,70 1,90 H [mm] 0,025 0,025 0,025 0,025 0,025 0,025 0,025 f (1/T)[Hz] 1,111 0,909 0,769 0,667 0,588 0,588 0,526 f (wavemaker) [Hz] 1,110 0,910 0,770 0,670 0,590 0,590 0,530 A [mm] 0,0125 0,0125 0,0125 0,0125 0,0125 0,0125 0,0125 filenames Data001 Data002 Data003 Data004 Data005 Data082 Data006 probe1 amplitude 9, ,95 10, , ,71 10, ,3139 freq rad 6, , , , , , ,32869 phase 14, ,3609 6, , , , ,3663 freq hz 1, , , , , , , probe 2 amplitude 8,1097 7, , , , , ,1069 freq rad 6, , , , , , ,33094 phase 2, , ,9903 1, , , ,2821 freq hz 1, , , , , , , probe 3 amplitude 11,94 12, , , ,94 11, ,6242 freq rad 6,9809 5, , , ,9809 3, ,32929 phase 11, ,6826 6, , ,5025 5, ,0129 freq hz 1, , , , , , , surge amplitude 4,2702 6, , , , , ,61515 freq rad 6, , , , , , ,32881 phase 7, ,0263 5, , , , ,04009 sway freq hz 1, , , , , , , amplitude freq rad phase freq hz heave amplitude 3, , , , , , ,03039 freq rad 6, , , , , , ,3235 phase 2, , , , , ,0549 7,31749 freq hz 1, , , , , , , roll amplitude freq rad phase freqhz pitch amplitude 0, , , , freq rad 6, ,7166 3, ,66437 phase 7, , ,482 yaw freq hz 1, , , , amplitude 0, freq rad 3,70918 phase 2,30585 freq hz Page 14 of 26

15 2.4 RESULTS Free Decay Tests Decay tests were carried out for both configurations. Figure 3and 4 show a heave and surge decay time history for Cfg I, when the model was released at approx. 100mm away from the equilibrium position. A Least Squares fit was made to the data using a function of the form: =+ cos+sin where,,,, are constants determined by the Least Squares analysis. Figure 6 Heave Free Decay test, (Cfg I) Figure 7 Surge Free Decay test, (Cfg I) The same tests were repeated for Cfg II and alsohere we obtained a good fit with the measurements (see Figure 3 and 4). Page 15 of 26

16 Figure 8 Heave Free Decay test, (Cfg II) Figure 9 Surge Free Decay test, (Cfg II) Page 16 of 26

17 2.4.2 Monochromatic Wave Tests The principal responses of interest are in surge and heave of the submerged cylinder. For the most part the responses in surge and heave were regular and it was possible to calculate an RAO, for a small number of frequencies, harmonics and/or other distortion was observed in the surge and heave response and for a subset of these the distortion was such that a sinusoidal function could not be satisfactorily fitted and so an RAO could not be calculated. The results were in general very high quality. The response of the cylinder in pitch was also regular at most frequencies but due to the moorings the system was stiff in pitch and the natural frequency was well above the frequency range of the tests. Additionally, for cfg i, the pitch excitation was low and so the motion was insignificant, for cfg ii the pitch excitation was higher and some motion was observed particularly at higher wave heights. For this geometry and waves coming from head-on Linear theory predicts zero excitation for surge, sway and yaw. In keeping with this the response in was low in these modes at most frequencies however at some narrow bands of frequencies motion was generated in these modes and in a subset the motion was extreme. For monochromatic waves, an example of the measurements undertaken for every test run is shown in Figure 10. This plot shows regular waves measured by the three wave probes in the top row. The plot also shows regular response in surge and heave, regular but small response in pitch and minimal movement in sway, roll and yaw. Figure 10 Time Series for a single test run (Data157) Page 17 of 26

18 Figure 11 Time Series for a single test run. Figure 11 shows a more complicated response than Figure 10 did, this is typical of a minority of the observations with significant non-linear response evident. The wave probes show a 3x larger wave than in the previous figure, as such distortions (deviations from sinusoidal) in the water surface are more evident. The response in surge is regular, the response in pitch is larger than in Figure 10. The response in heave shows significant motion at double the wave frequency, this is evidence of the non-linear response of the system. The response in roll, sway and yaw are all increased when compared to Figure 10. Page 18 of 26

19 Figure 12 gives the cfg i RAO s for heave and surge. In both cases there is no significant difference between the results for the three wave amplitudes tested this indicates that the device is operating within the linear range. The RAO s predicted by a preliminary numerical model are also indicated on Figure 12 the agreement between numerical and experimental data is good for both modes. Figure 12: Monochromatic waves. Heave & Surge RAO for Cfg I Figure 13 and 14 show the RAO measurements for Cfg II. Here we can see that the heave has a resonant period around 2.4s and the surge around 3.5s. The results are no longer the same for all wave heights we can see that the response is non linear with larger waves having lower normalised response as might be expected. In both modes the high frequency (low period) results are close to linear while closer to the resonance the differences in the response emerge. The results from a preliminary numerical model are over plotted in figures 13 & 14 this model uses a simple quadratic damping term (a force proportional to velocity squared is applied at the body mass centre) to account for viscosity and vorticity forces. The results of this model are encouraging. Page 19 of 26

20 Figure 13: Monochromatic waves. Surge RAO for Cfg II Page 20 of 26

21 Figure 14: Monochromatic waves. Heave RAO for Cfg II Page 21 of 26

22 2.4.3 Panchromatic Wave Tests The last series of tests includes the panchromatic waves. Figures 15 & 16 show a comparison of the pseudo-rao for heave and surge for configurations I & II respectively. The pseudo-rao is the ratio of root mean square of position signal to root mean square of wave elevation signal. In both graphs the agreement between measured and simulated values is encouraging. Figure 15: Panchromatic waves. Standard Deviation for Heave & Surge in configuration I. Page 22 of 26

23 Figure 16: Panchromatic waves. Standard Deviation for Heave & Surge in configuration II. Page 23 of 26

24 2.5 ANALYSIS &CONCLUSIONS The motions of a submerged horizontal cylinder moored in waves were investigated using both numerical and experimental methods and in resonant and non-resonant configurations. The results show that the simulations based on linear potential theory agree very well with the experimental observations at operating points that are away from the resonant response of the body. With this observation the implementation of these simulations is therefore validated. The linear model over predicts the motions of the bodies at wave periods close to the natural period. In this case the addition of a quadratic damping term to the time domain simulation gives very good agreement with experiment. Within the wave period and amplitude range tested the comparison indicates that a quadratic damping coefficient that is independent of both wave period and amplitude is appropriate. No power take off forces were present in this experiment. Inclusion of PTO forces will alter the relative importance of the quadratic damping forces so that even though a real WEC might operate close to resonance in one or more modes the importance of the quadratic damping in a real WEC could be expected to be intermediate to that in the two configurations presented in this paper. In other words introduction of PTO forces to a device could be expected to reduce motion and therefore reduce the importance of non-linear hydrodynamic forces. The demonstrated level of agreement between simulation and experiment is a prerequisite for numerical optimization of wave energy converters. The work reported in this project is a step towards numerical optimization of wave energy converters based on validated numerical simulations. The data collected in this project is to be made available under an open data arrangement so that other research groups might also benefit. Page 24 of 26

25 3 MAIN LEARNING OUTCOMES 3.1 PROGRESS MADE Progress made in the project includes: Experimental measurement of the response of a generic shape to waves. Comparison of the measured results with simulated results. Validation of the implementation of Cummins equation. Generation of an estimate of terms neglected by linear theory, e.g. viscous forces Validate the results produced by the radiation diffraction solvers Expansion of inviscid time domain simulations and frequency domain calculations to include terms representative of viscous forces. 3.2 PROGRESS MADE: FOR MARINE RENEWABLE ENERGY INDUSTRY In the long term validation and extension of the frequency domain calculation and the time domain simulation used in the WEC device optimisation software will allow the optimisation to better represent real world performance of the WEC devices. The optimisation will then produce locally optimal devices that are more relevant to the real world leading to higher possibility of developing an economically viable WEC device. 4 FURTHER INFORMATION 4.1 SCIENTIFIC PUBLICATIONS Costello, R., Padeletti, D. and Ringwood, J.V.. "Comparison of Numerical Simulations with Experimental Measurements for the Response of a Modified Submerged Horizontal Cylinder Moored in Waves." Proc. OMAE, San Francisco, Available online at: Garcia-Rosa, Paula B., et al. "Hydrodynamic Modelling Competition-Overview And Approaches." (2015). Lawson, M., et al. "COER Hydrodynamic Modeling Competition: Modeling the Dynamic Response of a Floating Body Using the WEC-Sim and FAST Simulation Tools." (2015). 4.2 WEBSITE &SOCIAL MEDIA Page 25 of 26

26 Infrastructure Access Report: APPENDICES Page 26 of 26 COERverFB