Offshore wind energy
Gebruik van ondergrondinformatie in planologie om onderhouds- en aanlegkosten te minimaliseren In order for offshore wind to become a cost-effective renewable energy technology, further cost reduction is needed, all the while minimising the impact of offshore wind farm development on the environment. The future generation of wind farms will also face new installation challenges in deeper and increasingly more hostile environments. Whether you are an offshore contractor, energy utility, or engineering company, we can assist you throughout your design, installation, operation & maintenance, and decommissioning phases.
Our specialty expertise in waves, currents, • Cable and pipeline routing, burial depth geotechnics, geology, and morphology - and their assessment, protection methods, and risk dynamic interaction - is of key relevance for offshore assessment. wind projects. We develop knowledge and tools for the industry that mitigates and minimizes risks to Geology, Geophysics and Geotechnics guarantee safe, reliable, sustainable, and cost-efficient • Identification and assessment of potential operations. Our specialised consultancy, applied geological hazards with methods such as in-situ research, and integrated studies pertaining to offshore characterisation of the subsurface; wind energy focus on: • Geotechnical analysis of offshore foundations and assessment of geohazards such as cyclic Hydrodynamics liquefaction; • Metocean conditions, in both fatigue and extreme • Installation techniques, such as pile installation conditions (pertaining to waves, water levels, (hammering, vibrating, drilling etc.) and cable currents, wind, icing and ice loading, air- and water burial (jetting, ploughing, trenching, self-burial). temperature, seismicity, marine growth, etc.); • Hydrodynamic loads, due to currents and This wide range of topics situates Deltares as a unique (breaking) waves, such as slamming loads, ringing partner for your offshore wind project. eW employ loads, loads on secondary structures, and fully- a wide range of tools: from laboratory-scale models nonlinear fatigue analysis. to numerical models and from field measurements to data-driven analysis methods. By combining the Seabed dynamics strength of multiple tools, we can determine the • Scour and scour protection for all type of offshore optimal solution for your project. foundations and infrastructure; • Seabed morphodynamics including sand wave analyses and the prediction of seabed changes during the lifetime of an offshore project; Hydrodynamics Offshore wind energy
Metocean conditions
The development of offshore structures, such as • ORCA (van Os & Caires, 2011) offshore wind turbines and offshore high-voltage Spatial statistical analysis tool to carry out stations, often starts with a metocean study that metocean studies; determines design fatigue- and extreme-loading • Delft3D (Roelvink & Van Banning, 1995) conditions. At Deltares, we frequently conduct Simulation of two- and three-dimensional metocean studies for our clients, providing them processes related to water and coastal morphology; with relevant atmospheric and hydrodynamic • SWAN (Booij et al., 1997) parameters such as: Numerical model for the computation of wave conditions in shallow water with ambient currents; Wind speed and wind direction at various • OceanWave3D Paulsen, Bredmose, and Bingham (2014) levels, wave heights, wave periods, wave Fully nonlinear potential flow solver; • Meteo Dashboard direction, current velocity/direction, and An integrated software system that collects, stores Figure 4 Spatially varying significant wave heights and peak periods in an offshore wind park, generated with SWAN. water levels. and presents measured and forecasted meteo- and hydrodynamic data. With experts drawn from a wide range of disciplines, Deltares can also provide expert analysis on:
Snow and ice accretion criteria, sea ice conditions, seismicity, air temperature and density, seawater salinity and density, marine growth, water quality, and seismicity.
Figure 6 Meteo Dashboard: an integrated software system that Figure 5 Boat landing during inspection and maintenance of an collects, stores and presents measured and forecasted meteo- and Figure 2 Annual wave rose at a selected location generated with ORCA. offshore wind turbine. hydrodynamic data per turbine.
ORCA, Delft3D, and Meteo Dashboard are tools developed an integrated software system that developed by our specialists at Deltares. These tools collects, stores, and presents all relevant measured are in continual development, providing us with a and forecasted meteo- and hydrodynamic data at nuanced understanding of the solutions we provide for the individual wind turbine level. our clients. Figure 1 Extreme value analysis of significant wave heights. Additionally, we employ our knowledge on Research & Development environmental processes to contribute to integrated In addition to the assessment of metocean conditions, research projects, such as: Modelling tools we also provide more fundamental research and Implemented knowledge of environmental processes, development in the course of our commercial projects. • MERMAID: Planning, design, and operation of field measurements, data-driven analysis, and state- Such projects pertaining to metocean conditions innovative multi-purpose offshore platforms of-the-art numerical models play a central role in our forecasting at offshore wind farms have included: incorporating aquaculture and other renewable studies so that we may give the best advice to our clients. energy technologies (see Figure 7). Deltares A tailored approach is determined for each study based • Meteo Dashboard: A decision-5support system for provided assessment of the environmental impact, on end objectives and the appropriateness of each tool. Figure 3 Annual current roses in four wind farm sites generated with planning operation and maintenance activities at technical feasibility, and economic effects to this Our state-of-the-art numerical metocean tools include: Delft3D offshore wind farms for cost minimisation. Deltares project for such an installation. Hydrodynamics Offshore wind energy
Persistence statistics – Establishes procedures for OpenFOAM® (i.e., Jacobsen et al. (2012) and Paulsen, carrying out workability and accessibility analysis. Hydrodynamic loads Bredmose, and Bingham (2014)). Our involvement in the development of these tools enables us to cultivate Numerical modelling of waves, currents, water levels At Deltares, we have many years of experience in in-depth understanding of the numerical models, in Deltares operates a number of regional and global the assessment of coastal and offshore structures. addition to their application and limitations. models of waves, tidal currents, and water levels. These In collaboration with our clients, we apply this dedicated local models are designed and adjusted knowledge to further optimise offshore structures. Research & Development according to project needs. Accurate numerical In addition to involvement in the commercial sector, modelling is an essential aspect of metocean studies, We use numerical methods, physical model tests, Deltares has also been involved in research and especially for areas not located near a measurement and expert knowledge from the preliminary design development projects related to the field of hydrodynamic Figure 7 Multi-purpose offshore platforms: renewable energy and station, sites with a complex bathymetry, or in an area phase to final design validation and verification. modelling and fluid structure interaction, such as: aquaculture. where wave-current interaction plays an important Within the field of hydrodynamic loading, we role. SWAN, a phase-averaging, shallow-water wave provide solutions for topics such as: • FLOW-GBS: The development of an alternative model, and Deltares’ state-of-the-art open-source offshore wind turbine foundation for monopile Expertise software, Delft3D, can be applied for the numerical Nonlinear slamming and “ringing” loads, design. Deltares contributed to knowledge in Statistics of environmental conditions using ORCA modelling these complex processes. loads on secondary structures, loads installation and ballasting, the cyclic response of We apply our knowledge on environmental processes soil, scour protection design, and wave loads; on moored floating structures and their and statistics to translate individual parameter data Weather window analysis for marine installations • JIP-Wifi I & II: Cultivate deeper understanding into joint probabilities, confidence intervals, and the The installation of an offshore wind park additionally mooring lines, but also less obvious topics of extreme breaking wave impacts on fixed wind evaluation of field measurements. For this purpose our presents logistical challenges, which requires such as water replenishment rates inside turbine foundations. Deltares provided wave specialists have developed the ORCA software tool, to the coordination of supply and support vessels, monopiles for corrosion monitoring. statistics, breaking impacts and better load analyse the required metocean data. The ORCA toolbox installation jack-ups, and transfer of personnel, which computations; has five main functionalities and each dealing with a are all weather-restricted. Statistical analysis and • JIP-GBS: Improve the engineering methods specific aspect of data analysis: forecasting of expected weather windows is therefore Modelling tools of transport and installation of gravity based essential for the planning of marine installations. In order to provide you with the best possible studies wind turbine foundations. Deltares focused on Data validation – Establishes necessary procedures and advice, we make use of several state-of-the-art hydrodynamic loads during installation and for the determination of a “good dataset”. These To support clients with decision making during numerical models and top-of-the-line physical model assessment of seabed interaction; include procedures for reading different types of data, installation and maintenance activities in an offshore testing facilities (see the section on physical model • TO2-Floating Wind: Optimisation of floating analysis of gaps in time series, data visualization, wind farm, Deltares has developed Meteo Dashboard, testing at the end of this document). Since no study is offshore wind turbines. Deltares provided numerical data comparison, error statistics and plots, and data an integrated software system which collects, stores, the same, we determine the optimal approach for each modelling of motions of the floating wind turbine correction; and presents measured and forecasted meteo- and study: which of these tools are most appropriate and and calculation of the loads on the mooring system. hydrodynamic data for each wind turbine. The Meteo how should they be deployed. Normal conditions – Establishes necessary procedures Dashboard includes a detailed forecasting system, Expertise for the determination of mean climates, including with high-resolution hydrodynamic modelling For numerical modelling of waves, currents, and fluid- Nonlinear fatigue analysis data classification, generation of wave roses, data providingforecasts of waves, currents and water levels structure interaction, we employ the following state- During the lifetime of the structure, the continually transformation and definition of mean climate at each wind turbine location in the proposed offshore of-the-art tools, in addition to in-house developed shifting of hydrodynamic forcing may lead to fatigue scenarios, among other procedures; wind farm. engineering tools: of critical components. State-of-the-art fatigue computations are normally carried out using linear or Extreme conditions – Establishes procedures for • OpenFOAM: Two-phase Navier-Stokes/VOF solver, lower order wave theory. However, as shown in Figure 9 extreme value analysis, including collection of peak- extended with waves2Foam (Jacobsen et al., 2012); and in Paulsen et al. (2013), this may lead to a significant over-threshold data, collection of annual maxima • OceanWave3D: Paulsen, Bredmose, and Bingham underestimation of inline forces. To accurately data, defining the optimal threshold for estimation of (2014); Fully nonlinear potential flow solver; characterize the nonlinear steepening of waves, the the generalized Pareto distribution parameters, return • ComFLOW: Single-phase Navier-Stokes/VOF solver problem must be addressed with fully nonlinear value estimation, and fitting of statistical distributions, specially designed for free surface flows; potential flow theory. At Deltares, we have many among other procedures; • StarCCM+: Multi-purpose CFD tool. years of experience with this nature of computations through our in-house solver, OceanWave3D. Thanks Sea state analysis – Establishes procedures for sea From the beginning, Deltares has been involved as a to in-depth numerical optimisation of the solver state analysis, including best-fits of different spectral main stakeholder in the development of ComFLOW. In algorithm, these computations can be carried out forms to discrete spectral data, estimation of sea state recent years, Deltares has also been integrally involved fast and efficiently, making the method applicable for wave statistics (e.g.: number of waves, H0.1%, etc.), Figure 8 Ice accumulation on the blades of an offshore wind turbine in the development of new and even more advanced accurate determination of fatigue loads based on long among other procedures; (Source: http://www.windpowerengineering.com). numerical tools based on the open-source CFD-toolbox time series. Hydrodynamics
Slamming loads Floating structures The largest forces on offshore structures are often Floating offshore wind turbines and floating wave observed during breaking wave impacts. Here, the energy converters are promising technologies for Figure 14 Wave loads, caused by wave diffraction, on deck Figure 9 Comparison between measurements, full space structure is exposed to an impulse-type loading in further unlocking offshore energy potential. At of gravity based foundation for an offshore high voltage resolving CFD and linear and non-linear potential flow the free surface zone, which may lead to substantial Deltares, we are involved in the development of station. computations. structural vibrations, or failure. To accurately capture these new technologies by applying and improving these type of impacts, the full Navier-Stokes equations, our physical and numerical modelling tools in in conjunction with a surface-capturing scheme, must combination with universities and industry partners. be solved. Two well-validated numerical models, Bruinsma et al. (2017) is an example of the validation specially designed for this nature of computation and application of OpenFOAM for modelling a moored are available at Deltares: ComFLOW, developed in floating wind turbine (see Figure 15). The knowledge collaboration with several universities and industrial on floating structures has been expanded further partners, and OpenFOAM®, the open-source CFD in projects such as JIP-GBS, where hydrodynamic toolbox, extended by the wave generation toolbox loads on a GBS foundation for offshore wind turbines waves2Foam, which adds additional functionality and were investigated during physical modelling of the Figure 15 Numerical modelling of the motions of a moored accuracy to the model installation and touchdown of the structure (see Figure floating wind turbine foundation in irregular waves. 16). . Figure 10 Physical model tests of slamming wave impacts Ringing loads on monopile foundations. The natural frequencies of offshore structures are Corrosion and water replenishment normally well-separated from the leading-order In recent years there has been an increased awareness frequencies of the incident waves. However, higher- of the risk of corrosion inside monopiles. This order forcing from steep and near-breaking waves awareness is mainly stimulated by inspections and may excite the structure at its natural frequency, decommissioning of existing foundations in the causing violent structural vibrations, known as event of higher-than-expected corrosion levels. A “ringing”. A potential redesign of the structure can commonly used corrosion protection system, ICCP, be avoided by considering these higher harmonic can cause acidification of the bulk fluid, which may Figure 16 Physical modelling of the installation of a gravity Figure 11 Numerical modelling nonlinear forces earlier in the design phase. damage internal cables or other fittings. To reduce based foundation for offshore wind turbines of gravity based wind turbine foundations where too much stagnant water inside the monopole, water among others the wave run-up and slamming loads were At Deltares, we have many years of experience with replenishment holes are commonly used. modelled. fully nonlinear “ringing” load computations for various types of offshore structures. Our research within At Deltares, a tool coupling hydrodynamic flows “ringing” and nonlinear wave forcing is carried out and water quality (Deltares’ DELWAQ model) has in close collaboration with the Technical University been developed. The hydrodynamic flow model has of Denmark and University of Oslo (see e.g. Paulsen, been validated against physical model experiments Bredmose, Bingham, et al. (2014)). performed in one of the physical model facilities at Figure 12 Physical Deltares (see Figure 17). With this tool, Deltares is Figure 17 Physical and numerical modelling of water model tests of gravity Loads on secondary structures able to determine wave action and pressures inside the replenishment inside monopiles. based wind turbine Secondary steel such as boat landings, ladders, and monopile, the effect of marine growth, flow velocities foundations, where platform decks are often located in the free surface through replenishment holes, and pH levels of the fluid among others the zone, making them vulnerable to impacts from in the monopile for representative met-ocean wave run-up was breaking waves, wave diffraction, and wave run-up, conditions. This information can be used to investigated. as can be seen in Figure 14. These forces cannot be provide advice on the positioning, size, and accurately estimated by the Morison equation due location of water- and air-replenishment holes. to impact-type loading and edge effects. At Deltares, we are experienced in the assessment of loads on Flow amplification secondary structures with physical model tests (see With detailed CFD simulations, the flow amplification e.g. de Sonneville et al., 2015). Furthermore, physical around bottom-fixed offshore foundation structures modelling is used for validation of our numerical models can be calculated (see Figure 18). Using local metocean in order to deliver accurate numerical assessments of conditions, this information can be used to determine Figure 18 Numerical modelling loads on secondary structures. maximum flow velocities for the design of infield and of the flow amplification around a jacket support structures Figure 13 Measured and computed wave run-up at the export cables connected to an offshore high voltage for offshore high voltage stations to determine the lateral side of a gravity based wind turbine foundation. system. maximum hydrodynamic loads on infield and export cables. Seabed dynamics Offshore wind energy
Scour and scour protection Expertise • Edge scour prediction model: An empirical- Scour prediction Local erosion of seabed material around offshore mathematical Edge Scour Prediction Model Local erosion of seabed material leads to significant foundations (scour) can become so severe that it validated against field measurements; scour holes, which can jeopardize foundation stability. jeopardizes foundation stability. Our specialists • OSCAR: Laboratory-validated scour prediction and An estimate for the maximum expected scour depth is have ample experience with the assessment of scour protection design tool for various spud can required for structural design and in decision-making scour around offshore foundations, such as (but shapes developed within JIP OSCAR (Raaijmakers, into whether counter-measures (scour protection) not limited to) monopiles, jackets, gravity-based De Sonneville, et al., 2013); will be required. The time rate of scouring is of foundations, and jack-ups. Within projects where particular interest in the installation phase, due to scour development is critical, we are capable of The dynamic scour prediction model and edge scour its determination of the time at which a critical scour creating and testing scour protection layouts to aid prediction model are in-house tools developed by depth is reached and scour protection needs to be our clients in their design process. Deltares experts. The OSCAR-software has been applied. developed within the framework of JIP OSCAR, a Joint At Deltares, we use our expert knowledge and Industry Project together with the offshore drilling physical model tests from the preliminary design industry on the topic of “Offshore SCour And Remedial Figure 20 Test setup in the Atlantic Basin with a scour protection phase to final design validation and verification, measures” (Raaijmakers, De Sonneville, et al., 2013). installed around the Borssele offshore high voltage station. covering topics such as: Research & Development Predictions of local scour and edge scour In addition to the many commercial projects regarding around offshore structures, design of the scour and scour protection, we have been involved in the following research and development projects: conceptual scour protection layouts, physical modelling to validate scour JIP HaSPro: Joint-industry project to be completed in protection designs, evaluation of field September 2019, pertaining to the development of a data, but also less obvious topics such as clear, generic, and science-based comparison between estimations of winnowing depths. different scour protection methods. These methods are developed to directly support decision makers Figure 19 Edge scour patterns around a monopile foundation. in selecting the most suitable and cost-effective scour protection methods for each situation. In this Deltares has carried out numerous research projects, Modelling tools project, existing methods (based on loose rock) are which have resulted in the development of scour To provide you with the best advice, we use our expert optimized, and innovative scour mitigation methods prediction formulae for the equilibrium scour depth Figure 21 Test setup in the Atlantic Basin with a scour protection knowledge, field measurements, data-driven analysis, are investigated (proof-of-concept) and prepared and the time rate of scour development under installed around an offshore structure. and top-of-the-line physical model testing facilities for offshore field tests. Inclusive to this project is an offshore conditions. We have developed sophisticated (see the section on physical model testing at the end of extensive test campaign consisting of scale model modelling techniques with digital video cameras that this document). As each study is unique, we determine tests on three different scales; allow insight into processes during storm conditions. the optimal approach by tailoring tools and approach Extensive knowledge and experience is not only to your needs. • JIP Ecofriend: This TKI Wind Op Zee funded available for monopiles but also for gravity-base project starts in November 2018 and concerns foundations, jackets, and jack-ups. For predictions of local scour depths around offshore offshore eco-pilots with scour protections and structures, edge scour depths at foundation protection other structures focused on restoring oyster reefs Conceptual scour protection edges, and scour protection designs for jack-up and increasing fish population and biodiversity in Our specialists have ample experience in creating platforms, we make use of the following state-of-the- offshore wind farms. The project involves, amongst conceptual scour protection layouts for a wide range art numerical tools, as well as in-house developed others, offshore monitoring campaigns, modelling of offshore structures including monopiles. Within engineering tools: of environmental parameters and interpreting projects where scour development is critical, we are relations between ecological success of an eco- capable of creating and testing scour protection • Dynamic scour prediction model: Laboratory- friendly measure and environmental parameters; layouts to help our clients in their design process. In and field- data validated scour prediction model • JIP OSCAR: Development of a software package for Deltares (2017b), we provide an overview of various for offshore foundation structures (Raaijmakers & scour prediction and design of a scour protection scour strategies and mitigation measures for the Figure 22 Test setup in the Atlantic Basin with a scour protection Rudolph, 2008; Raaijmakers, Joon, et al., 2013); based on over 100 physical model tests; Hollandse Kust (zuid) wind farm. installed around an offshore structure subject to a significant • FLOW-Scour: Determination of the influence of seabed lowering. scour at monopile foundations and researching of alternative protection methods and materials. Seabed dynamics Offshore wind energy
Physical modelling As a result of evolving techniques, computational Deltares has world-class laboratory facilities for Seabed morphodynamics capabilities, and research, we can update our in-house testing scour protection systems (such as the Atlantic developed tools constantly in order to provide the Basin). In testing, the foundations, scour protection Short-term and long-term morphological changes best analysis possible, while significantly reducing layouts and the hydraulic conditions are scaled and of the seabed are important parameters in the uncertainties and accompanying risks. installed in the Atlantic Basin of Deltares (see Figure design of offshore wind farms. The stability and 5.5). For example, Deltares performed physical model energy yield of wind turbines, in addition to risk Research & Development Figure 23 Test setup in the Delta Flume serving as tests for the Borssele offshore high voltage stations assessment for electricity cables, are all influenced We apply our modelling tools in various commercial validation of the scour protection designs. in order to determine scour patterns and stability of by the seabed morphology and its evolution. For projects concerning seabed morphodynamics. In the scour protection around the jacket structure (see example, the migration of mobile sand waves may addition to the development of our capabilities in Figure 21). cause seabed elevation differences of up to several seabed dynamics on the basis of commercial projects, meters. we have been involved in the following research and Multiple scale models can be installed in each test to development projects: minimise the total number of tests, and are defined At Deltares, we use data-driven methods and based on the results of previous studies. Specific numerical models to gain insight into seabed FLOW-Cables: Reduce monitoring costs by developing attention is given to the foundations exposed to a large morphodynamics for prediction of future knowledge and tools to monitor and predict cable hydraulic load (e.g. due to a shallower water depth or a evolution of the seabed. With our expertise in burial depth over the life time of an offshore wind farm. more exposed location to waves), or where a significant seabed morphodynamics, combined with studies JIP Cables Lifetime Monitoring: An ongoing (2018) lowering of the bed is expected (see Riezebos et al. for advising hydrographic offices and offshore initiative between Deltares and >30 partners to further Figure 24 Example of a 3D-stereo measurement of the (2016)). engineering companies and development of state- mitigate the risk of cable failure during the lifetime of scour development around a jacket structure following of-the-art morphodynamic models, we cover the a submarine cable project. a test performed in the Atlantic Basin In order to accurately observe and quantify the following topics: performance of the tested scour protections, several Expertise (visual) measurement techniques are used. Digital Predictions of sand wave migration in Predictions of future and hindcast of past seabed photographs of the test section are taken before and sandy seabeds, assessment of areas prone morphodynamics after each test. During the tests, the performance Deltares has ample experience in analysis, to large seabed variations, prediction and of the scour protection is monitored by means of characterization, prediction, and hindcasting the underwater cameras and cameras placed inside monitoring of power cable burial over time, morphodynamic behaviour of mobile seabeds. the scale models. Lastly, before and after each test, and implications of changes in seabed levels Deltares has ample experience from projects situated 3D-stereophotography is used to obtain a 3D image of for foundation structures. throughout the North Sea, such as the Borssele and Figure 25 the complete area around the scale model. Hollandse Kust (zuid) wind farm zones, among others. Investigation of alternative scour protection: Artificial vegetation around a monopile Scour protection usually consists of granular material: filter and armour. However, Deltares has also built up Modelling tools knowledge on alternatives, especially within the Joint We use numerical and data-driven analysis methods, Industry Project HaSPro. We can therefore advise our coupled with bathymetrical data, hydrodynamic data clients on the full range of scour protection options and expertise about comparable sites, to support our (gravel bags, rubber mats, block mattresses, collars seabed morphodynamic assessment. Since each study and frond mats). area is unique, we determine an optimal approach on the specific site conditions and available data, making Evaluation of field data use of the following tools: Combining knowledge from field research and laboratory experiments plays a key role in our • Delft3D:(Roelvink & Van Banning, 1995): research projects. Together with industrial partners, Simulation of two- and three-dimensional we evaluate bathymetric surveys and assess expected processes related to water and coastal morphology; scour development and the performance of the scour • Morphology toolbox: Data-driven analysis toolbox Figure 27 Multibeam echo sounding data of a sand wave field 50 protection. for analysis and prediction of seabed level changes km offshore Egmond aan Zee, displaying straight sand waves and in mobile environments in high detail; superimposed megaripples. Data from several offshore wind parks have provided • Cable route optimization tool: (Roetert et al., unique insight into the long-term stability of a 2017): Data-driven analysis tool for determination Deltares has access to North Sea historic data, such Figure 26 Analysis of scour protection performance from dynamically stable scour protection and into the of cable routing within offshore wind farms with as the detailed seabed survey depicted in Figure field data, Offshore Windpark Egmond aan Zee (OWEZ). development of scour at the edge of the scour protection. respect to seabed dynamics. 27, and historic data from international waters. In Seabed dynamics Geology, geophysics and geotechnics
Borssele (Deltares, 2014, 2016a) and Hollandse Kust (zuid) (Deltares, 2016b) wind farm zones commissioned by the Dutch Enterprise Agency (RVO. Geology and geophysics Expertise nl). Both the studies are used as input for tenderers Geological and geophysical desk studies of both wind farms and comprise of the state-of-the Knowledge of the structure and properties of the Deltares advised RVO and RWS on geological, art methodology concerning predictions of seabed subsurface is important for many offshore activities, geophysical and geotechnical survey strategy for morphology. A highly-detailed spatial overview of sand like sand extraction, wind turbine foundation design, wind farm planning and development (Hollandse wave migration speeds for the Hollandse Kust (zuid) cable trajectories and alternative energy solutions. Kust Zuid and Hollandse Kust Noord Wind Farm Figure 29 Sand wave mobility (horizontal migration in offshore wind farm is displayed in Figure 29. Zone). The desk studies and quick scans focused on meters per year) found for the Hollandse Kust (zuid) Deltares develops and applies a range of measurement the overview and assessment of available data, the offshore wind farm, displaying a south to north increasing Cable route optimization methods and software to explore the subsurface. We building of a stratigraphic framework, the implications trend (Deltares, 2016b). To date, methods to optimize cable route layout in lead the quest for innovative solutions for a wide for geotechnical characteristics and possible (geo) offshore wind farms are only based on a flat seabed and range of subsurface challenges facing society. Our hazards (Deltares, 2015, 2017a). do not take seabed dynamics into account. For offshore specialist advice is grounded firmly in state-of-the- wind farms, migrating seabed features in the form of sand art field measurements, equipment and methods, waves are of great importance and may significantly laboratory tests and computer models and covers alter the position of the seabed over the life time of the the following subjects: wind farm. This will in turn change the burial depth of power cables, and may even leave cables exposed. Identification of potential geological hazards, in-situ characterisation of the subsurface In Roetert et al. (2017) a combination is made between (2D and 3D), in situ analysis of geological cable burial depth and seabed morphodynamics. Making Figure 30 ‘Cost-field’ surrounding two wind turbines. The use of seabed predictions, we can calculate cable burial sequence and of geotechnical properties, red line indicates the horizontally-optimised cable route depths over time and subsequently adjust the proposed characterisation of the subsurface based on between the two turbine locations. routing to ensure a minimum guaranteed cable burial existing geophysical data and quantification depth. Such a calculation takes into account the risks and constraining of geological hazards. of cable failure, the morphodynamic environment, and detailed analyses, the dimensions, migration rates, other characteristics such as trenching costs, turbine and the evolution of individual bed forms, such as sand production capacity, UXO’s, edge scour locations, and waves, sand banks, and tidal channels are quantified existing infrastructure. This can be done by either Research & Development using a cross correlation technique, a dz/dt analysis, altering the initial cable position in the vertical plane, In addition to the many commercial projects regarding and 1D and 2D spectral analyses (Van Dijk, 2008). In such as deeper cable burial in areas where future seabed the geology and geophysics of the seabed, we have been order to provide the highest level of detail, we employ lowering is expected, and by altering its position in the involved in the following research and development an automated process, which analyses thousands horizontal plane, such as diverting the power cables projects: of transect points resulting in accurate and localised around risk prone areas (see Figure 30). predictions of seabed mobility. • Assessment sand mining areas: the subsurface Prediction of cable burial depth with DTS of prospected sand mining areas is studied as part The behaviour of sand waves depends on local Detailed information about the burial depth of cables of the Environmental Impact Assessment. The environmental conditions. From field investigations, it is can significantly reduce the risk of cable failures. assessment includes suitability of present sand often complicated to determine the dominating factors Consequently, O&M costs can be reduced due to less layers; occurrence of disturbing layers, such as controlling variation in sand wave shape and dynamics. down time, reduced insurance fees, fewer surveys, and clay and peat; and presence of fines in the sand for Damen et al. (2018) found that the mode of sediment only planned marine operations. mud plume modelling. The subsurface of the areas Figure 31 Geological interpretation of the subsurface at the Hollandse transport may be a major control on sand wave is characterized with existing and newly acquired Kust (noord) windfarm depicting available borehole locations (top dynamics. To develop further insight into the mobility To obtain such detailed information (both in time geological and geophysical data and information. figure) and a schematic geological cross section (bottom figure) of the bed forms, we apply Deltares’ process-based and space) concerning the burial depth of cables, the An extensive sampling campaign of newly acquired (Deltares, 2017a). morphodynamic numerical model, Delft3D. Delft3D pre-installed optical fibre in most export and infield vibrocores is used as input for mud modelling; solves the differential equations describing the major cables can be used as a sensor. Namely, this cable • Shallow 3D seismics: in cooperation with Geophysical surveys physical processes of water and sediment motion. Such allows for DTS monitoring (Distributed Temperature TNO Geological Survey of the Netherlands, an Geophysical techniques are powerful tools in the sediment transport alters seabed morphology, which in Sensing): measurement of the temperature profile experimental survey acquiring high resolution 3D characterization of the geometry and properties of turn impacts local hydrodynamics. along the cable. In previous studies, Deltares has found seismics on the North Sea was performed. The survey the subsurface. Deltares applies such tools offshore a strong correlation between the burial depth and the resulted in high resolution information of the upper to identify and visualize sand and clay layers in the Site investigation studies RVO temperature that is measured by the optical fibre: a part of the subsurface, providing new insights in the upper tens of meters below the seabed. Such analysis In the analysis of seabed morphodynamics, Deltares larger burial depth limits the diffusion of heat and architecture and composition of the subsurface and provides useful information for, for example, marine performed site investigation studies for both the results in a higher temperature of the optical fibre. clearly delineating 3D features such as channels; contractors and for RWS. Offshore wind energy
• Plaxis 2D and 3D: A finite element program Geotechnics developed for the analysis of deformation, stability, and risk factors in geotechnical engineering; A quarter of the total investment in the development • Abaqus: A software suite for 3D finite element of an offshore wind turbine is spent on its analysis and computer-aided engineering used in foundation. Consequently, cost and risk reductions complex geotechnical problems; in pile installation and increased longevity of piled • Anura 3D: 3D software for modelling and foundations are valuable assets in a competitive simulation of deformations and soil-water- global offshore market. Key to innovative structure interaction using the Material Point foundation designs and competitive installation Method; techniques is an in-depth understanding of the • Deltares probabilistic toolkit: The Probabilistic complex soil behaviour during both installation Toolkit developed by Deltares enables probabilistic and subsequent cyclic wave and wind loading. analyses, bandwidth calculations, and sensitivity Recent advances in numerical simulation of pile analyses on a wide range of models and cases; installation and monopile behaviour under different • Deltares D-cycle: In-house developed software Figure 32 Acquiring in situ measurements from the subsurface. loading conditions provide the opportunity to that is often used in wave-induced liquefaction develop such an understanding. assessments.
Field site investigation: boreholes and CPT’s At Deltares, we use advanced modelling techniques Deltares has worked together with university and and experiments in our laboratory facilities in commercial partners to acquire and analyse in-situ conjunction with expert knowledge to support our samples and measurements from the subsurface, such clients from the preliminary design phase to the as boreholes and cone penetration tests. The main final design validation and verification, covering partners are the University of Utrecht, TNO, and Marine topics such as: Sampling Holland. The combination of borehole and CPT data provides direct measurement of geological Pile installations, pipeline and cable and geotechnical properties, in addition to calibration trenching assessment, anchor dragging of seismic data. and burial studies, geotechnical design
Figure 33 Example of an acquired borehole displaying Existing seismic data processing and interpretation of gravity based structures, liquefaction, the first four meter of the subsurface. Seismic data contain valuable information about the decommissioning, salvage and wreck architecture and the characteristics of the subsurface. removal operations, geotechnical data Figure 35 Visualisation of the soil density after monopile installation The processing of seismic data depends on the purpose assessment and third party review. using MPM (JIP SIMON). of the investigation (e.g. shallow or deep) and on the method of data acquisition. Elaborate processing of Research & Development the data can yield useful information, such as shear To ensure that we can support our clients with cutting wave velocity parameters and, by extension, on the Modelling tools edge technology and expertise we are involved in shear strength of the subsurface for wind turbine To provide you with the best studies and advice, we use research projects. Over the last years we have been foundations. Furthermore, Deltares has successfully our expert knowledge, field measurements, data-driven involved in the following research and development applied these techniques to existing data in the area analysis and top-of-the-line physical model testing projects: of the Groningen gas field to improve understanding of facilities (see the section on physical model testing at the stability of the subsurface. the end of this document). Each study is tailored to the • JIP HyPE-ST: Joint Industry Project: Hydraulic appropriate tools and approach to best meet your needs. Pile Extraction – Scale Tests (JIP HyPE-ST), a TKI Geotechnical risk maps and parameters Wind Op Zee funded project. The project starts Geological desk studies provide a geological framework For study and analysis of geotechnical problems we in November 2018 and concerns a series of and identify potential geo-hazards in a proposed make use of the following state-of-the-art numerical laboratory-scaled tests for complete (mono-)pile wind farm area. Deltares has developed the workflow and engineering tools: removal by means of pressurisation in the Deltares and numerical techniques to link available geological water-soil-flume. properties to geotechnical properties and risk, thereby • Deltares Material Point Method (MPM): A 3D • JIP SIMON: Joint Industry Project: Simulation of Figure 34 Example of an analysed borehole displaying quantifying and visualizing uncertainty and risk. software package which is and applied to various Monopile Installation (JIP SIMON), a TKI Wind Op soil resistance and behaviour type for the first eight The available data can be in-situ or derived from geotechnical problems including monopile Zee funded project. The project aims to improve meter of the subsurface. comparable geological systems (analogues). installation; the assessment of the installation of monopiles at Geology, geophysics and geotechnics Offshore wind energy
offshore sites and generate better understanding Expertise of post-installation soil response due to Site investigation and laboratory testing Marine salvage support services salvage services include: geotechnical and coastal environmental loads. This is achieved through Deltares has expertise in establishing specifications for In marine salvage operations, the complexity of the morphology, environmental impact assessment, advanced numerical studies on pile installation geotechnical and geophysical site investigation data situation and operational/environmental requirements dredging techniques and offshore operations, and loading processes using the Deltares in-house during the feasibility, preliminary, and final design call for a multidisciplinary approach, in which Deltares horizontal directional drilling, wreck stability, MPM software. This software has been developed phases. We have unique laboratory facilities for testing is uniquely situated. We are an established partner in data acquisition and evaluation, risk management to overcome the limitations of classical Finite of soil samples with specialised equipment such as the worldwide salvage industry, with a proven track- and assessment, onsite support, and dispute and Element Method (FEM). With this 3-D software, the cyclic-, bender-, internal strain- or compressive/ record and broad experience. Our expertise in marine arbitration support. full ground installation processes, such as impact extension triaxial testing, K0-CRS- and incremental and vibration-driven piles, can be modelled. loading K0-testing, as well as static and dynamic DSS. • Layered soil: Cone penetration testing (CPT) Figure 37 Tri-axial testing equipment and soil samples. is used widely to determine the geotechnical properties of soils and to analyse the stratigraphy. Foundation design However, it is difficult to estimate a representative Our geotechnical experts can advise on geotechnical value for cone resistance, however, when thin aspects for all types of offshore foundations, such as layers of sand and clay or peat alternate due to the driven or drilled monopiles, suction piles or buckets, influence of surrounding layers on the measured and gravity-based foundations. Additionally, our cone resistance. This results in an average value, experts can advise on the design of seabed preparation and therefore the effect of multiple thin layers is activities, such as pre-dredging, soil improvement, studied in our laboratories; and placement of gravel beds or filters for stability • Probabilistic analysis: Geotechnical engineering and prevention of residual displacements due to cyclic faces large uncertainties compared with other loads. Preliminary and final design is carried out engineering domains, due to estimates of soil according to national and international geotechnical and rock properties typically based on a limited guidelines (such as API and DNV), while incorporating amount of site investigations. To counteract this, new insights gained during the process of site we have developed a probabilistic analysis, which investigation, laboratory testing, and design. Deltares results in an optimised design; is also represented in the API/ISO committee for Figure 37 Tri-axial testing equipment and soil samples. • Anura 3D: Large deformations and soil–water– offshore foundation design. Figure 38 Visualisation of 3D Finite Element Method (FEM) calculations. structure interactions exist in many engineering problems, such as scour development around Numerical simulations of cyclically-loaded offshore offshore structures. Deltares has aided in the foundations are primarily carried out in PLAXIS and development of the Anura3D software to overcome ABAQUS for all stages of design. Furthermore, D-Pile is the challenges of modelling the hydrodynamical used for monopole foundation design and pile groups coupling, large deformations, and contact (API standards included), which also incorporates ship problems. impact on foundations. Finally, D-Cycle is employed in the determination of excess pore pressures due to cyclic loading on gravity-based structures. Both D-Pile and D-Cycle are developed in-house.
Geohazards Geohazard analysis is an essential part of the design process. Such analysis allows for design iteration for prevention of high maintenance costs or premature failure. Our expertise in the analysis and mapping of geohazards includes: geological anomalies (e.g. sub- sea volcanoes, turbidity currents, mud channels), subsoil heterogeneity, slope stabilities, creep of a gently sloping seabed, sand bank migration, over-pressurized sands present in the subsoil, and Figure 39 Pile group in D-Pile, example of Plasti-Poulos module. Figure 40 Visualisation of wreckage location used in marine salvage assessment of earthquake-prone areas. operations. Figure 36 Effects of dragging anchor on rock berm in GeoCentrifuge Experimental facilities Offshore wind energy
Deltares is your best partner for water and The size and different type of available wave flumes Pumping system subsurface research. With our wide range of make it possible to test a large range of offshore • Max. pumping capacity: 0.6 m3/s facilities - from laboratories and field studies to support structures. A few example projects are: • Current-wave-angle: 0º and 180º test arrays and simulators - we can provide tailored • Scour and bed protection around bottom-fixed research solutions matching your requirements offshore structures Atlantic Basin and budget. An overview of the facilities available • Forces and wave run-up on bottom-fixed offshore The Atlantic Basin is a multifunctional facility, and at for your testing needs at Deltares, from small to structures present, the only one of its kind in the world. With its large, is: • Forces and motions during installation of gravity- total size of about 650 m2, waves and (tidal) currents based foundations can be simulated. The test section contains: The Scheldt Flume, Atlantic Basin and Delta Flume can be used to test typical monopile Scheldt Flume A sand pit of 130 m2 and a depth of 0,5 m The Scheldt Flume is a state-of-the-art wave flume with and jacket foundations for offshore wind which is used for modelling of scour processes. a total length of 110 m. The flume has wave generators turbines at a scale of 1:1 to 1:50. at both sides, enabling the use of one for wave generation and one for wave dissipation. The flume The wave generator consists of 20 wave paddles can also be split into two flumes (Eastern and Western driven by a hydraulic system. The independently Scheldt Flume) so that two projects can be performed controlled wave paddles make it possible to generate Figure 43 Atlantic Basin overview photo taken from the wave maker simultaneously, with each section 55 m long. At one oblique waves and are equipped with Active Reflection towards the test section with two jacket support structures for the side of the flume, a pumping system is installed. Compensation to compensate for waves reflected by Borssele Offshore High Voltages Stations. Additionally, the wave generators are equipped with structures in the basin. A current can be generated via Active Reflection Compensation, which measures a pumping system either following or opposing the propagating waves and compensates for reflections. waves. Depending on project-specific needs, the basin Additionally, wave board control for random second- layout can be modified in such ways as constructing order waves is able to compensate for spurious waves. narrower internal wave flumes. Additionally, the The Scheldt Flume can be used to test typical offshore Atlantic Basin is equipped with state-of-the-art wind structures at a scale of 1:30 to 1:50. In such instrumentation, a gantry crane, and access bridges. studies, aspects of such subjects as armour stability, wave impact loading, and the determination of the The Atlantic Basin can be used to test typical offshore relevant hydraulic conditions for design purposes can wind structures at a scale of 1:20 to 1:40. This basin be evaluated. The two wave generators provide the is a wide flume for investigations of hydrodynamic option of testing test structures by approaching waves loads, specific design details, bed protection, and from both sides. morphological impacts of hydraulic structures. The Figure 41 Scheldt Flume overview photo. On the left the Eastern combination of wave generation with a pumping Scheldt Flume and the far right the Western Scheldt Flume. Additionally, this facility provides the opportunity to system allows for realistic simulation of sea waves study the influence of opposing propagating waves on interacting with a current. This is not only of interest Figure 44 Atlantic Basin photo of the test section with three monopile such topics as erosion and dissipation. It is possible for research on wave-current interaction but also foundations for offshore wind turbines and three different type of to construct all manner of foreshore bathymetries essential for a number of situations, such as scour scour protection designs. in our Scheldt Flume, both fixed-bed and mobile-bed around offshore structures. foreshores to ensure the wave behaviour in the model will be the same as in prototype. Finally, projects Technical specifications: requiring current can be carried out due to the powerful • Wave flume pumping system in place. • Length: 75 m • Width: 8.7 m Technical specifications: • Height: 1.0 m • Wave flume Wave characteristics • Length: 110 m • Frequency range: 0 to 2 Hz • Width: 1.0 m • Max. wave height: 0.45 m • Height: 1.2 m Pumping system Wave characteristics • Max. pumping capacity: 3.0 m3/s • Frequency range: 0 to 2 Hz • Current-wave-angle: 0º and 180º Figure 42 Scheldt Flume detailed testing of new type of scour • Max. wave height: 0.4 m protection designs around monopile foundation for offshore wind. Experimental facilities Offshore wind energy
by the facility’s 10m high wave paddle, which employs applying high gravitational forces, which represents an hydraulic cylinders for horizontal translation. A water acceleration in time for the processes involved in Geo- depth of 6.9m is estimated to be the optimal water Engineering. Each test is developed specifically for the depth at the wave board for reaching the highest project and a selection of alternatives can be compared significant wave height for which the wave height quickly. distribution is modelled accurately. To date, such a magnitude of waves cannot be generated anywhere The Deltares GeoCentrifuge stands out from else in the world. others in that it combines 300 G-forces, a large research container of 2 m3, and the expertise Technical specifications: • Wave flume and skills of our technicians. • Length: 291 m • Width: 5.0 m Examples of recent tests are: • Height: 9.5 m • Pile foundations: assessment of ageing and group Wave characteristics effects. • Frequency range: 0.05 to 1 Hz • Anchor pulling experiments: assessing the damage • Max. wave height: 4.5 m done to cables and lines by dragging anchors.
GeoCentrifuge Technical specifications: Deltares has a unique facility with one of the largest • Maximum G-forces: 300 GeoCentrifuges in the world. • Container dimensions: 2x1x1 m3 • Length of arm: 5.5 metres The GeoCentrifuge is used to simulate processes to • Maximum speed: 456 km/h scale that can take months in reality. This is done by • Maximum revolutions: 3.7 per second
Figure 45 Wave run-up against a 1 m diameter monopile foundation for offshore wind turbines in the Delta Flume.
Delta Flume The Delta Flume is a unique test facility where on real scale the effect of extreme coastal structurescan be tested. It is:
The largest artificial waves of the world for accurate large-scale testing.
Globally, there is a large demand for testing coastal and offshore structures under natural (prototype) conditions, since natural materials and hydrodynamics cannot always be properly scaled. The Delta Flume is 300m long, 7m to 9.5m deep, and 5m wide, with a modelling area depth of 9.5m, length of 183m, and an extra 75m section of 7m in depth. The remaining part of the flume length is covered by the wave generator. The deepest section of the flume has a length sufficient for modelling structures such as dikes, while the shallower section allows for modelling of gentle foreshores over a length of about 250m, which could Figure 46 Delta Flume with a 1 m diameter monopile foundation for offshore optionally be combined with dunes. Individual waves wind turbines and a realistically scaled scour protection. up to 4.5m height (Hs = 2.2m) can also be generated Figure 47 The GeoCentrifuge at Deltares. References About Deltares
Booij, N., Holthuijsen, L., & Ris, R. (1997). The” (2014). An efficient domain decomposition strategy SWAN” wave model for shallow water Coastal for wave loads on surface piercing circular cylinders. Deltares is an independent institute for applied Deltares will develop the roles into a balanced mix, Engineering 1996 (pp. 668-676). Coastal Engineering, 86, 57-76. research in the field of water and subsurface. enabling a response optimally attuned to different Bruinsma, N., Paulsen, B., & Jacobsen, N. (2017). Paulsen, B.T., Bredmose, H., Bingham, H.B., & Throughout the world, we work on smart requirements of different stakeholders at different Validation and application of a fully nonlinear Jacobsen, N.G. (2014). Forcing of a bottom-mounted solutions, innovations, and applications for times. The roles in combination provide essential numerical wave tank for simulating floating offshore circular cylinder by steep regular water waves at finite people, environment and society. Our main focus added value to our stakeholders, and are the pillars in wind turbines. Ocean Engineering. depth. Journal of Fluid Mechanics, 755, 1-34. is on deltas, coastal regions, and river basins. defining strategic targets and operational plans. The Damen, J.M., Van Dijk, T.A.G.P., & Hulscher, S.J.H.M. Paulsen, B.T., Bredmose, H., Bingham, H.B., & Managing these densely populated and vulnerable roles mutually reinforce each other, and together they (2018). Spatially varying environmental properties Schløer, S. (2013). Steep wave loads from irregular areas is complex, which is why we work closely cover all stages of the innovation cycle: from developing controlling observed sand wave morphology. Journal waves on an offshore wind turbine foundation: with governments, businesses, other research and acquiring new scientific knowledge to valorisation of Geophysical Research: Earth Surface. Computation and experiment. Paper presented at the institutes, and universities at home and abroad. Our and validation of new knowledge and models in real de Sonneville, B., Hofland, B., Mowinckel, A., & ASME 2013 32nd International Conference on Ocean, motto is Enabling Delta Life. As an applied research world projects. Paulsen, B.T. (2015). Wave Impact Loads on Offshore Offshore and Arctic Engineering. institute, the success of Deltares can be measured Gravity Based Structure. Paper presented at the ASME Raaijmakers, T., De Sonneville, B., & Rudolph, D. in the extent to which our expert knowledge can be Offshore products and services 2015 34th International Conference on Ocean, Offshore (2013). Joint Industry Project “OSCAR” on Offshore used in and for society. For Deltares, the quality of We tailor our products to your specific needs and and Arctic Engineering. SCour And Remedial measures. Paper presented at our expertise and advice comes first. requirements to ensure the usability and applicability Deltares (2014). Morphodynamics of Borssele the The Thirteenth International Jack-Up Conference for your project. Our knowledge areas comprise: Wind Farm Zone; prediction of potential seabed level Conference, London. At Deltares, the safety of visitors, suppliers changes during the lifetime of offshore wind parks. Raaijmakers, T., Joon, T., Segeren, M., & Meijers, and employees comes first. We always have • Metocean conditions & large-scale hydrodynamics Ref: 1210520-000-HYE-0002; draft report, dated 23 P. (2013). Scour: to protect or not to protect, that’s • Wave-structure interaction ‘Safety in Mind’. December 2014. the question! Feasibility of omitting scour protection. • Scour and morphodynamics Deltares (2015). Geological study Hollandse Kust Paper presented at the Proceedings of the International • Handling of solids (zuid) Wind Farm Zone. Ref: 1221136-000-BGS-0006; Conference European Wind Energy Association 2013. • Marine geotechnics final report, dated 22 December 2015. Raaijmakers, T., & Rudolph, D. (2008). Time- Corporate Social Responsibility • Geohazards Deltares (2016a). Morphodynamics of Borssele dependent scour development under combined current As an independent research institute in the area of • Environmental impacts Wind Farm Zone WFS-IV, WFS-III and WFS-V; Prediction and waves conditions-laboratory experiments with water, subsurface and infrastructure, Deltares works • Transients in pipeline systems of seabed level changes between 2015 and 2046. online monitoring technique. Paper presented at the on innovations, solutions, and applications for people, • Geophysical surveys Ref: 1210520-000-HYE-0012; final report, dated 25 Proc. 4th Int. Conf. Scour Erosion, ICSE, Tokyo. environment, and society. We fulfil a leading role January 2016. Retrieved from: http://offshorewind. Riezebos, H., Raaijmakers, T., Tönnies-Lohmann, A., in knowledge development and knowledge sharing In addition to offshore wind energy, we serve clients in rvo.nl/file/view/42115002/report-morphodynamics- Waßmuth, S., & van Steijn, P. (2016). Scour protection for the sustainable development of deltas, coastal a variety of markets: bwfs-iv-iii-v-deltares-2016. design in highly morphodynamic environments. Paper regions and river basins. “Enabling Delta Life” is our • Pipelines and cables Deltares (2016b). Morphodynamics of Hollandse presented at the Scour and Erosion: Proceedings of mission and it drives what we do. We work together • Wave, tidal and blue energy Kust (zuid) Wind Farm Zone; Prediction of seabed the 8th International Conference on Scour and Erosion closely with government authorities, companies, • Oil & gas exploration and production level changes between 2016 and 2051. Ref: 1230851- (Oxford, UK, 12-15 September 2016). research institutions, and NGOs at home and abroad. • LNG transport and storage 000-HYE-0003; final report, dated 22 December Roelvink, J., & Van Banning, G. (1995). Design and We have demanding standards for our research and • Dredging and mining 2016. Retrieved from: http://offshorewind.rvo.nl/ development of DELFT3D and application to coastal consultancy and we want to be improving all the • Coastal and harbour development file/view/47910422/report-morphodynamics-of- morphodynamics. Oceanographic Literature Review, time. When it comes to explaining our work, we have • Marine safety and remediation hollandse-kust-zuid-wind-farm-zone-deltares. 11(42), 925. an active and transparent approach. Corporate social • Salvage consultancy Deltares (2017a). Geological study Hollandse Kust Roetert, T.J., Raaijmakers, T.C., & Borsje, B.W. responsibility is anchored in our corporate processes (noord) Wind Farm Zone. Ref: 11200513-002-BGS- (2017, June 25-30). Cable route optimization for and management systems. 0001; final report, dated 23 March 2017. offshore wind farms in morphodynamic areas. Paper Deltares (2017b). Scour and scour mitigation presented at the The 27th International Ocean and Knowledge and innovation For more information: [email protected] for Hollandse Kust (zuid); Recommendations for Polar Engineering Conference, San Francisco, CA, USA. The mission of Deltares is to develop, acquire, apply, foundations and cables. Ref: 11200864-002-HYE- Van Dijk, T.A.G.P., Lindenbergh, R.C., Egberts, P.J.P. and disseminate integral, multidisciplinary knowledge 0001; final report, dated 27 September 2017. Retrieved (2008). Separating bathymetric data representing and knowledge products related to living and working from: http://offshorewind.rvo.nl/file/view/53711152/ multi-scale rhythmic bedforms: a geostatistical and in delta (coastal, estuarine, and riverine) areas, on technical-note-scour-and-scour-mitigation-deltares. spectral method compared. Journal of Geophysical an internationally leading level. With this, Deltares Jacobsen, N.G., Fuhrman, D.R., & Fredsøe, J. Research, 113(F04017). doi: 10.1029/2007JF000950 supports public authorities, private parties, and (2012). A wave generation toolbox for the open‐source van Os, J., & Caires, S. (2011). How to Carry Out society in their operations and ambitions, related to CFD library: OpenFoam®. International Journal for Metocean Studies. Paper presented at the ASME 2011 sustainable development of delta areas: Enabling Delta Numerical Methods in Fluids, 70(9), 1073-1088. 30th International Conference on Ocean, Offshore and Life. Paulsen, B.T., Bredmose, H., & Bingham, H.B. Arctic Engineering. Offshore wind energy
For more information: [email protected]
Deltares is a leading, independent, Dutch-based research PO Box 177 institute and specialist consultancy for matters relating 2600 MH Delft, The Netherlands to water, soil and the subsurface. We apply our advanced T +31 (0)88 335 82 73 expertise worldwide, to help people live safely and [email protected] sustainably in delta areas, coastal zones and river basins. www.deltares.nl