SFI BLUES is running a webinar series from 0900-0945 every second Friday. Topics range from technical presentations to industry experience within the applications relevant to SFI BLUES. The webinars are open to partners in the centre. The webinars are recorded and made available to the partners here. Suggestions for webinar topics are always welcome.

Friday May 6th, 2022 – Ann Kristin Sperrevik and Marta Trodahl (MET): Modelling the coastal ocean

Human activities at sea such as shipping, oil exploitation, fisheries, and recreation largely occur in the coastal ocean and shelf seas. These regions are also important for marine life as they serve as spawning and feeding grounds for several fish stocks and are hot spots for primary production in the ocean. Circulation estimates from operational ocean forecasts are key components of emergency response services such as search-and-rescue and oil spill mitigation, while data archives of the ocean state during a historic period can be used e.g. for studies of physical processes.

A plethora of physical processes are important for setting the current ocean state, ranging from large-scale stirring by oceanic storms to small-scale turbulent mixing. In order to reproduce a realistic “model ocean”, the models need to represent these processes in some way. Due to computational limits, not all processes are resolved on the model grid. The large spread in spatial and temporal scales, as well as the turbulent nature of the ocean, makes ocean predictions a very complex task.

A crucial part of an ocean prediction system is the initial conditions – the ocean state prescribed on the start of a model simulation. Shortcomings and errors in the initial conditions will limit the skill of the model results. To ensure that the initial conditions are as close to the true ocean state as possible, observations are fused with model output through data assimilation, to produce an improved estimate of the ocean state.

In this talk, we will discuss some of the challenges of producing skillful ocean predictions for the Norwegian coastal and shelf seas, and the role of combining observations and models through data assimilation in improving the modelled ocean circulation

Friday April 22st, 2022 – Afaf Saai, SINTEF Industry: Aluminium connection in dissimilar-material structures and marine environment

In the steel-dominated offshore structures, aluminium alloys can be introduced to improve the strength to weight ratio of some components. However, mixing and matching these two metals to achieve a unique combination of strength and lightweighting require careful consideration of the design of their connections to avoid galvanic corrosion. The connection technologies and their performances in marine environment are key challenges to enable increased use of aluminium in the novel offshore concepts.

A short overview comparing the different technologies used for connecting aluminium in dissimilar material structures will be presented with focus on their advantages and disadvantages for offshore environment. Then, the activities in 2022 around aluminium-stainless steel bolted connection, including both numerical and experimental activities, will be introduced.

Friday April 1st, 2022 – Jens Bloch Helmers, DNV: Coupling of advanced ocean wave models and marine hydrodynamics

For most marine structures dimensioning responses are caused by combinations of large and steep waves. With introduction of new technologies, it is evident that classical wave models applied in engineering communities, often provide misleading input to marine hydrodynamics. Not only when describing critical wave kinematics but also with respect to provide realistic frequency of occurrence. The latter is essential for reliable assessments of many important design loads.

Ocean wave models and marine hydrodynamics evolve independently. Due to increasing model and software complexity, it has become challenging to combine these technologies in industrial applications. Which methods to combine? What needs do we have? What challenges? How to deal with them? Overview of an open-source platform for utilizing advanced wave models in time domain marine hydrodynamics is provided. Examples and lessons learned from using this platform in a range of commercial and academic tools are presented.

Friday March 18th, 2022 – Elin Dalen-Rasmussen, Statens Vegvesen: BOLC – a digital twin in 3D of the Bjørnafjorden floating bridge

One look is enough – a pilot for model-oriented project management in real time

For almost two years, the development project Bjørnafjorden has been working on finding a solution to model-oriented project management to reduce the risk in the bridge project. Now the project presents the pilot to a new model-oriented project management portal.

The project management portal with the working title “BOLC” (Bjørnafjorden Open Live Centre) is a dashboard with real-time information that gives the project manager a full overview of project and management information. All the roles of the builder will benefit from the solution.

VIDEO: Modellbasert project management in practice

This is a digital twin of the bridge project which means that we as a builder get a complete picture of project status in the construction phase via PC, mobile or whatever web-based solution you want to use. The gains are previously available decision information related to costs, progress, and quality. We can thus be a little more proactive in managing the project. The Dashboard portal is an open  web-based  interface  that harvests data from ordinary project and process tools that apply model-based data flow to open data formats.

Friday March 4th, 2022 – Sébastien Laflèche, SINTEF Ocean: Wave homogeneity in hydrodynamic testing facilities

Experimental testing of large structures requires control of the environment and especially of the waves over a large area. It has been shown that for most basins, a uniform motion of the wavemaker will generate a spatially inhomogeneous wave field, even before reflection occurs. There is thus a need to either remove or predict those patterns of inhomogeneity. Techniques to improve the uniformity of the wave field have been developed, but only for specific basin geometries.

In this talk, we will show the experimental results revealing those patterns, and we will indicate their possible causes, as well as solutions to improve wave homogeneity. To this end, an efficient linear model to describe wave fields in basins of arbitrary geometry but constant depth will be introduced.

Friday February 18th, 2022 – Serag-Eldin Abdelmoteleb, NTNU: Preliminary Sizing and Optimization of Semisubmersible Substructures for Future Generation Wind Turbines

The continuous technological development of offshore wind turbines is imperative to their cost-competitiveness in the future global energy market. Several key development areas have been identified as having high potential for reducing the levelized cost of energy and opening up new markets for offshore wind. Two of the most anticipated developments are future generation large wind turbines with higher power ratings and floating foundations for offshore wind turbines. There is thus a need for developing large floating substructures that are capable of hosting future generation wind turbines.

This work presents the preliminary sizing of two semi-submersible platforms for supporting a 25 MW turbine through a design space search using a simplified parametric analysis. The platforms studied in this work are upscaled versions of reference platforms: UMaine VolturnUS-S which was designed to support the IEA15MW wind turbine and INO WINDMOOR which was designed to support the WINDMOOR12MW wind turbine. While the former carries the turbine on a central column, the latter places the turbine on one of the three side columns. The IEA 15MW wind turbine is upscaled theoretically, while the upscaling procedure for the platform is based on exploring the effects of different geometrical parameters of the substructure on basic characteristics of the floating system such as steel mass, static pitch at rated thrust, and natural periods, including the tower bending natural frequency.

To be able to explore a large number of design variations in a computationally efficient manner, some simplifying assumptions are adopted in this study. These assumptions include the following: only motions on vertical-longitudinal plane are considered (i.e., surge, heave, pitch, and fore-aft bending of the tower); added mass is estimated using strip theory with 2D coefficients; and constant steel thickness across all structural members is assumed. Furthermore, detailed mooring system design is not carried out. The final substructure designs are selected to have minimal steel weight at a specified maximum allowable static pitch angle while also satisfying constraints related to the natural periods of the system as well as geometrical constraints on draft, freeboard and maximum dimension of the substructure. The main goal of this procedure is to establish a good starting point for further detailed design of the studied concepts. Compared to theoretically upscaled substructures, the designs resulting from the proposed simplified parametric analysis have significantly lower steel mass for the same allowable static pitch angle as the original reference designs as well as stiffer tower first bending mode.

To verify the results of the aforementioned simplified upscaling process, coupled aero-hydro-servo-elastic simulations using OpenFAST software are carried out for candidate design points.  The results are compared to the simplified parametric analysis, and differences in the dynamic responses of the designs are discussed.

This is joint work from Serag-Eldin Abdelmoteleb, Alejandra Escalera Mendoza, Carlos R. dos Santos, Erin E. Bachynski-Polić, Todd Griffith, Luca Oggiano

Friday February 11th, 2022 – Trygve Kristiansen, NTNU: A multi-torus solar island concept

Solar power is foreseen to play a major role in the future energy mix. As part of this mix, large-scale harvest of solar power at sea and on reservoirs represent a significant global potential. For instance, by covering 1% of man-made reservoirs by solar islands, one can produce about 400 GW, the same amount as that planned for floating wind in the EU by 2050. Powering large cities by solar islands by near-shore solar islands is also a promising application which has received recent attention in Asia, among other places. Further, solar-island powered floating factories at sea, producing liquid fuel by recycling CO2 from the ocean, represent a significant contributor towards a carbon-neutral future.

To realize solar islands at large scale, highly cost-efficient marine sub-structures are needed. The structures must cover large water surfaces, and withstand waves and current. Structures that follow the waves at a large extent is foreseen as the most promising way. At present, floating membrane concepts and multi-modular concepts are proposed. The multi-torus concept represents a third alternative. In this talk we will show results from model tests and numerical work that indicate that the multi-torus may serve as a viable concept, in that it follows the waves in realistic sea-states to a large extent.

Friday January 28th, 2022 – Sigurd Solheim Pettersen, DNV: Ocean Space Forecast

DNV has been working with ocean industries for 157 years and is already extensively involved in the new era for the ocean. We have identified the need for a comprehensive overview of how the blue economy will develop in the coming years.

In this presentation, we will discuss the key findings from DNVs new Ocean’s Future to 2050 report. This report highlights how the Blue Economy is entering a period of sectoral and geographic diversification.

These are the highlights:

  • Offshore wind will overtake the oil and gas sector to receive the largest investments in the Blue Economy
  • The Blue Economy will be dominated by Asia
  • There will be a 9-fold increase in demand for ocean space for aquaculture and energy production
  • The energy transition and increasing purchasing power of Asia will alter outlook for shipping
  • Aquaculture production to match capture fisheries by 2050

Friday January 14th, 2022 – Kristoffer Kjellså Jakobsen, Aker Solutions: Arctic Offshore Farming

Friday December 17th, 2021 – Trond Landbø, Dr. Techn. Olav Olsen: OO-Anchor – A new and innovative anchor design

Dr. Techn. Olav Olsen AS has developed a new and innovative anchor design for mooring of floating units. The anchor is a cost effective alternative to suction anchors and is suited for sediment soils such as clay, silt and sand. The purpose is to reduce cost related to fabrication and installation of anchors for floaters. Special focus has been on sharing of anchors between several floaters in a farm-configuration.
The anchor design is based on the philosophy of better utilization of the soil strength, a simple and automated fabrication process and simple and cost effective transportation and installation.
Norwegian patents have been granted and international patenting is ongoing.

Friday November 26th, 2021 – Muhammad Mukhlas, NTNU: Bag and floater motions of a fabric membrane cage

Bag and floater motions of a scaled fabric membrane cage model was investigated. The cage model consisted of an enclosing fabric (or a bag), an elastic floater, a mooring system, and an internal water mass. The model was moored in a towing tank and subjected to regular waves with different periods and steepnesses. Several interesting responses of the fabric membrane cage will be discussed: cage set-down, bag motion, and floater motion. Simplified numerical simulations were performed using WAMIT, which assumed a rigid cage model. A floater motions comparison between model tests and WAMIT results shows the importance of taking the bag and floater flexible modes into account when performing hydrodynamic analysis of a fabric membrane cage.

See also: https://www.sciencedirect.com/science/article/pii/S0889974621001365

Friday November 12th, 2021 – Erik Østby, DNV: READI JIP (REquirement Asset Digital lifecycle Information)

READI JIP (READI – – Shaping the future of digital requirements and information flow in the oil and gas value chain (readi-jip.org)):
“The Joint Industry Project (JIP) READI (REquirement Asset Digital lifecycle Information) addressing needs in the entire oil and gas capital value chain. Today owners, operators, EPCI contractors and suppliers in the oil and gas industry spend massive amounts of expert man hours to specify, implement and verify requirements versus design, yet repeatedly resulting in quality deviations, costly operations and safety issues in project execution and operation. READI JIP addresses this by establishing a platform for automated digital verification of requirements and design in the oil and gas industry, including governance and validation.

When in place, the platform will enable computers to read and perform automatic reasoning on requirements to validate consistency and verify engineering and operational data with accuracy at minimal cost and time expenditure from concept definition to decommissioning. Using advanced digital technology to reshape and automate current business processes:

• Strengthen the competitive edge of the oil and gas industry
• Improve quality, reduce failures and enhance safety in projects and operations of assets
• Accelerate digitalization and standardization in the global oil and gas industry
• Gain efficiency through automation of work processes in engineering, procurement and operation»

Erik will present the READI-project and also touch upon how the methods and the framework from READI can be applyed towards other industries, such as offshore wind.