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Predictive Surrogates for Aerodynamic Performance and Independent Sail Trim Optimization of Multiple Wind Propulsion System Configurations

Martina Reche-Vilanova, Sebastian Kaltenbach, Petros Kourmoutsakos, Harry B. Bingham, Manuel Fluck, Dale Morris & Harilaos N. Psaraftis

Wind Propulsion Systems (WPS) have gained significant attention as a means of decarbonizing shipping. Limitations in available deck space, emissions reduction targets, and regulatory compliance have led to a wide array of potential WPS configurations, each exhibiting distinct aerodynamic performance and requiring unique optimum sail trims for each unit due to complex interactions. This variability challenges existing aerodynamic models and optimization efforts for maximizing fuel savings. To address this, we present a novel methodology that, for the first time in WPS aerodynamic performance prediction, combines Computational Fluid Dynamics (CFD), independent sail trim optimization, and Machine Learning (ML) to develop surrogate models — Gaussian Process Regression and Feedforward Neural Networks — that rapidly predict aerodynamic performance with CFD-equivalent accuracy. These surrogates capture aerodynamic interactions across various WPS configurations, including unit number, deck arrangement, independent sail trim, hull characteristics, and wind conditions. While employing established ML techniques, our approach is novel in its resource-efficient generation of a comprehensive aerodynamic database, derived from the first in-depth independent trim optimization of a DynaRig case study. Our approach enables the modeling of complex, non-linear interactions that traditional interpolation methods fail to capture. Results show that the developed surrogate models achieve CFD-level accuracy, with an average error below 1 while significantly reducing computational time. This ML-enhanced framework facilitates extensive, rapid WPS design optimizations, supporting efficient integration into performance prediction programs (PPPs) and maximizing fuel savings and emissions reductions tailored to specific routes and wind conditions.Machine Learning; CFD-Simulations; Aerodynamic Performance; Wind Propulsion Systems; Green Shipping; Independent Sail Trim Optimization.

Journal of Sailing Technology / 2025
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A Linear Time Algorithm for Optimal Quay Crane Scheduling

Mathias Offerlin Herup, Gustav Christian Wichmann Thiesgaard, Jaike van Twiller, Rune Møller Jensen

This paper studies the Quay Crane Scheduling Problem (QCSP). The QCSP determines how a number of quay cranes should be scheduled in order to service a vessel with minimum makespan. Previous work considers the QCSP to be a combinatorially hard problem. For that reason, the focus has been on developing efficient heuristics. Our study shows, however, that the QCSP is tractable in the realistic setting, where quay cranes can share the workload of bays. We introduce a novel linear time algorithm that solves the QCSP and prove its correctness.

International Conference on Computational Logistics : Lecture Notes in Computer Science / 2022
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Optimization of Exhaust Covers in Marine Scrubbers

Mathias Poulsen*, Kim Sørensen, Thomas Condra

The number of marine scrubbers installed in industry has been on the rise over the past decade and is expected to continue in the coming years. Therefore, it is essential to ensure that the design of the scrubbers enables as an efficient operation as possible. In this study, an optimization of the exhaust cover inside an in-line scrubber was carried out. The optimization was done by combining a computational fluid dynamics model working on a simplified geometry with the method of feasible directions in order to reduce the pressure loss caused by the exhaust cover. The design is constrained in both height and width of the points making up the exhaust cover to ensure proper drainage of water and to avoid invalid designs. It was found that the optimized design reduced the pressure loss by 42% compared to the initial design. Furthermore, the scalability of the original design was investigated with the same height constraint enforced on the design variables. The result of the scalability analysis showed that the radius of the exhaust cover for the optimal designs scales linearly with the diameter of the scrubber, while the pressure loss was found to increase quadratically as the diameter of the scrubber increases.

Journal of Fluids Engineering / 2022
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Development and calibration of a model for packed bed marine scrubbers aboard ocean-going vessels

Mathias Poulsen, Henrik Ström, Srdjan Sasic, Kim Sørensen, Thomas Condra

Scrubbers have gained importance in the maritime sector following recent tightening of the emission legislation regarding sulphur. In this work, a model framework based on an Eulerian-Eulerian multiphase model for a packed bed marine scrubber has been developed. The framework account for both dispersed droplets and a packed bed, where sub-models for interfacial forces and heat- and mass transfer are applied for the respective regions. Additionally, a chemistry model and boundary conditions for the nozzles injecting seawater into the scrubber are also implemented. The model framework is calibrated using data from an ocean-going vessel, where the model predictions were within 3% of the measured pressure loss while the discrepancy in the gas and liquid temperatures were between 0.5% and 3.5%. The sulphur concentration predicted by the model varies between − 24% and 25%. However, the concentrations were within 5 ppm of the measured values for all but a single data set.

Chemical Engineering Research & Design / 2023
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When ‘sustainability’ becomes the norm: Power dynamics in the making of a new eco-label for low-environmental-impact, small-scale fisheries

Mathilde Højrup & Troels Jacob Hegland

In 2020, the Danish Ministry of Environment and Food launched a new state-led ecolabelling scheme for fish originating from small-scale, 'low-environmental-impact' fisheries; "Nature-friendly". The label was introduced to a domestic market where the vast majority of the fish landed by Danish vessels was already certified by the global leader in certification of (wild caught) fish products, the Marine Stewardship Council (MSC). MSC's high market penetration created a situation where especially small-scale fishermen felt that MSC certification had developed into a market norm without providing fishermen the benefits of demonstrating extraordinarily sustainable practices and thereby gaining competitive advantages. Rather, MSC's market penetration was perceived as undermining efforts to brand and market fish originating from small-scale fisheries as particularly sustainable. This article explores the processes that led up to the NaturSkånsom labeling scheme by applying a 'power in planning and policy framework' as an analytical lens. Through the NaturSkånsom process, the article investigates what happens when an ecolabel becomes a market norm, how small-scale fisheries actors who feel disadvantaged by such a development and environmental organizations form alliances, mobilize support and multiple resources to strengthen their positions in the political settings. The examination of this case highlights how stakeholders traditionally thought of as less resourceful can gain political influence. The article offers a glimpse into a possible, emerging future where those who perceive themselves as the most sustainable producers may increasingly view large and dominating ecolabels simultaneously as obstacles and forces for positive change.

Marine Policy / 2021
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Potential and Limiting Factors in the Use of Alternative Fuels in the European Maritime Sector

Matteo Prussi*, Nicolae Scarlat, Michele Acciaro, Vasileios Kosmas

The maritime sector is a key asset for the world economy, but its environmental impact represents a major concern. The sector is primarily supplied with Heavy Fuel Oil, which results in high pollutant emissions. The sector has set targets for deacrbonisation, and alternative fuels have been identified as a short-to medium-term option. The paper addresses the complexity related to the activities of the maritime industry, and discusses the possible contribution of alternative fuels. A sector segmentation is proposed to define the consumption of each sub-segment, so to compare it with the current alternative fuel availability at European level. The paper shows that costs and GHG savings are fundamental enablers for the uptake of alternative fuels, but other aspects are also crucial: technical maturity, safety regulation, expertise needed, etc. The demand for alternative fuels has to be supported by an existing, reliable infrastructure, and this is not yet the case for many solutions (i.e. electricity, hydrogen or methanol). Various options are already available for maritime sector, but the future mix of fuels used will depend on technology improvements, availability, costs and the real potential for GHG emissions reduction.

Journal of Cleaner Production / 2021
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Electrification of the seas: Foresight for a sustainable blue economy

Matthew J. Spaniol*, Hamidreza Hansen

Productive activity in the North Sea Region (NSR) is expected to intensify, diversify, and expand further offshore. Pressure to decarbonize and “electrify” the existing and emerging industries of the ocean economies offer an opportunity as the electrification of the seas has captured the imagination of industry and policymakers as a pathway to achieving sustainable growth. Using the methods of morphological analysis, thematic analysis, and structural analysis, this article identifies and reports on six innovation concepts for the electrification of the seas: Charging at wind farms; Charging at fish farms; Charging at thermal-powered platforms; Charging by floating solar panels; Charging at tidal plants; Charging at offshore container terminals. This article provides a base for entrepreneurship by generating insight into the affecting variables for each configuration as well as the identification of the strategic variables. It furthermore contributes a novel methodological approach to produce said understanding. The paper concludes with prospects for the electrification of the seas and charts a pathway for sustainable transition of the ocean economies.

Journal of Cleaner Production / 2021
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Anticipated innovations for the blue economy: Crowdsourced predictions for the North Sea Region

Matthew J. Spaniol*, Nicholas J. Rowland

The mission policy approach to the sustainable blue economy has identified as critical the ability to anticipate the emergence of a wide range of feasible innovations as they enter the transactional environment of organizations in the marine and maritime sector. This article contributes to that growing effort by harnessing the wisdom of the crowd and presents more than 60 crowdsourced, time-specific innovation forecasts expected to impact maritime, shipbuilding, ports, offshore wind, and ocean infrastructure. Data were collected in 2020 by the EU-funded Interreg VB PERISCOPE Project, a North Sea Region initiative to catalyze transregional innovation. The results can be used strategically to develop collaborative, transregional planning and policy for innovation based on data reflecting public expectations for the future. Years from now, this article can also act as a snapshot of public expectations at the onset of the decade.

Marine Policy / 2022
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Business ecosystems and the view from the future: The use of corporate foresight by stakeholders of the Ro-Ro shipping ecosystem in the Baltic Sea Region

Matthew J. Spaniol*, Nicholas James Rowland

Ecosystems are viewed as important sources of innovation. While contracts, rules, policies, and industrial standards have been identified as important for coordinating and aligning inter-firm relationships, tools for the collective, collaborative orchestration of ecosystems have yet to be fully identified and articulated by scholars. The core contribution of this paper, the authors contend, is that corporate foresight tools, as applied at the level of the ecosystem, have the potential to orchestrate ecosystems. To this end, the authors examine the practical use of corporate foresight tools, in this case, roadmapping and scenario planning, as employed by ECOPRODIGI, an Interreg Baltic Sea project designed to advance the EU's strategy for eco-efficient Sustainable Blue Economy in the Roll-on/Roll-off (Ro-Ro) shipping ecosystem. Results demonstrate how ecosystem-level foresight significantly differs from traditional foresight centered around a focal firm. Corporate foresight tools, as applied to an ecosystem: 1) Target a diverse set of ecosystem actors beyond the segment's focal firm, including complementary firms, investors, and non-market actors; 2) Engage ecosystem actors, rather than only the focal firm, in shared strategy development based on a diverse mix of foresight tools; and 3) serve to orient and reify the ecosystem by charting the collective anticipation of innovations, policies, etc., in a shared set of future options. In the end, the authors find that corporate foresight tools operate as constitutive elements of ecosystems, that is, the tools help enact the ecosystem not as an abstract concept but as a shared, lived reality.

Technological Forecasting and Social Change / 2022
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Offshore energy hubs: Cost-effectiveness in the Baltic Sea energy system towards 2050

Matti Juhani Koivisto*, Polyneikis Kanellas, Rasmus Bo Bramstoft Pedersen, Hardi Koduvere, Juan Pablo Murcia Leon

Offshore energy hubs connect large amounts of offshore wind to a hub from where the generation can be transmitted to onshore, potentially linking to multiple surrounding countries. The benefits of such hubs, and the related meshed offshore grid to connect them, have been investigated in the North Sea. The system-wide impacts of offshore energy hubs in the Baltic Sea are less studied; however, the region is seeing increased interest in offshore wind development. This paper uses detailed offshore wind generation simulations and energy system optimisation to investigate the cost-effectiveness of offshore energy hubs in the Baltic Sea in different scenarios towards 2050. The results show that the largest deployment of offshore energy hubs occurs when the energy system is highly electrified. The strongest development of the offshore energy hubs occurs in the southern part of the Baltic Sea.

Event21st Wind & Solar Integration Workshop - The Hague, Netherlands Duration: 12 Oct 2022 → 14 Oct 2022 / 2022
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