In a number of experiments and field tests of point absorbers, snap loads have been identified to cause damage on the mooring cables. Snap loads are basically propagating shock waves, which require special care in the numerical modeling of the mooring cable dynamics. In this paper we present a mooring cable model based on a conservative formulation, discretized using the Runge-Kutta discontinuous Galerkin method. The numerical model is thus well suited for correctly capturing snap loads. The numerical model is verified and validated using analytic and experimental data and the computed results are satisfactory.
Background
The transfer of offshore wind farm workers between transport vessels and wind turbines is a hazardous operation with a disproportionately high occurrence of "high potential" incidents. Motion sickness has been reported to affect offshore wind farm worker well-being, and has been identified as a job demand, especially during crew transfer and ladder-climbing operations.
This scoping review sought to determine the extent to which current research defines, describes, and quantifies MS among offshore wind farm workers and to identify relevant research gaps.
Methods
Using terms related to motion sickness and offshore wind farm operations, searches were conducted of the PubMed, Scopus, and Web of Science databases. Studies published in English between 1990 and 2024 were included.
Results
795 articles were retrieved, of which 11 articles met the inclusion criteria. The included articles describe MS as a job demand but do not clearly define it in the research context. Consequently, it remains unclear which symptoms of MS constitute a job demand and how workers are affected. Additionally, indications of motion sickness prevalence are required, using a clear definition which accounts for the wide range of subjective symptoms other than vomiting.
No research appears to have been carried out where motion sickness among wind farm workers has been studied as a broad occupational health issue within the offshore wind energy sector.
Conclusions
This review identifies significant research gaps concerning motion sickness among offshore wind farm workers. Motion sickness-related issues have either been overlooked, studied in isolation, or insufficiently addressed. These issues constitute empirical, methodological, and knowledge gaps, necessitating a need for systematic studies that address these research gaps in the context of the offshore wind energy sector.
Mobilization of residual oil droplets is the key process for enhanced oil recovery. Visualization of the droplet movement at a pore level provides insights on the underlying physical mechanisms. We couple a microfluidic droplet generator and a thin glass capillary to study the movement of oil droplets under salinity gradients with visualization of individual droplet movements. The driving forces that affect the movement of the droplets are discussed. We demonstrate experimentally that oil droplets in micro-confined channels can be mobilized and move against pressure under the concentration gradients of dissolved salts. The gradient-driven movement can be strong enough to drive a droplet through a narrow constriction in the middle of the capillary channel. The droplet movement can be understood by combining a Marangoni stress due to surfactant redistribution, electrostatic interaction and diffusiophoresis. This suggests that the abrupt change of salinity may be one of the physical mechanisms of smart waterflooding.
Multi-phase flow meters are of huge importance to the offshore oil and gas industry. Unreliable measurements can lead to many disadvantages and even wrong decision-making. It is especially important for mature reservoirs as the gas volume fraction and water cut is increasing during the lifetime of a well. Hence, it is essential to accurately monitor the multi-phase flow of oil, water and gas inside the transportation pipelines. The objective of this review paper is to present the current trends and technologies within multi-phase flow measurements and to introduce the most promising methods based on parameters such as accuracy, footprint, safety, maintenance and calibration. Typical meters, such as tomography, gamma densitometry and virtual flow meters are described and compared based on their performance with respect to multi-phase flow measurements. Both experimental prototypes and commercial solutions are presented and evaluated. For a non-intrusive, non-invasive and inexpensive meter solution, this review paper predicts a progress for virtual flow meters in the near future. The application of multi-phase flows meters are expected to further expand in the future as fields are maturing, thus, efficient utilization of existing fields are in focus, to decide if a field is still financially profitable.
This article develops a micro-level theoretical perspective of business influence in international negotiations. By drawing on organizational institutional theory, the article proposes that site-specific institutionalized norms can structure the nature and extent of business power. The article illustrates the value of this perspective through an illustrative case study of the International Maritime Organization (IMO) through interviews and participant observation of on-site dynamics during negotiations on environmental shipping regulation. The article shows how, in the case of the IMO, specific institutionalized norms and beliefs structure private actors’ possible influence and their claims to authority. In particular, strongly held beliefs about the nature of political deliberation in the IMO both constrain and enable business interests, sometimes overriding the general structural power of the shipping industry. This research implies that future scholarship of business power and lobbying should be attentive to specific institutionalized ideas structuring business actors’ range of legitimate activities, in particular in international institutions where individual negotiation sites can develop idiosyncratic norms and beliefs about the legitimacy of private actor participation.
Since the outbreak of COVID-19, its impacts on the maritime transportation and logistics field have been multi-dimensional. In addition to the green shipping corridor proposed by the Clydebank Declaration in the United Kingdom in 2021, port digitalisation and decarbonisation of the maritime industry have become focal issues in the field. The industry needs a new framework to offset the negative impacts of the pandemic and to accommodate integrated technologies comprising of artificial intelligence (AI), blockchain, cloud systems, internet of things (IoT) and others, which have been applied to the industry. Having considered these circumstances, this paper aims to propose the 6th-generation ports model with smart port (6GP) as a new framework for the port logistics industry in the post-COVID-19 period. The proposed 6GP contributes to providing business development strategy and port development policy for stakeholders in the industry in the post-pandemic era reflecting focal challenges such as digitalisation, decarbonisation, sustainability and smart transformation. It also contributes to expanding port devolution theory from the fifth-generation ports (5GP) to 6GP.
Purpose
The purpose of this paper is to investigate the impact of cloud computing (CC) on supply chain management (SCM).
Design/methodology/approach
The paper is conceptual and based on a literature review and conceptual analysis.
Findings
Today, digital technology is the primary enabler of supply chain (SC) competitiveness. CC capabilities support competitive SC challenges through structural flexibility and responsiveness. An Internet platform based on CC and a digital ecosystem can serve as “information cross-docking” between SC stakeholders. In this way, the SC model is transformed from a traditional, linear model to a platform model with the simultaneous cooperation of all partners. Platform-based SCs will be a milestone in the evolution of SCM – here conceptualised as Supply Chain 3.0.
Research limitations/implications
Currently, SCs managed holistically in cyberspace are rare in practice, and therefore empirical evidence on how digital technologies impact SC competitiveness is required in future research.
Practical implications
This research generates insights that can help managers understand and develop the next generation of SCM with the use of CC, a modern and commonly available Information and Communication Technologies (ICT) tool.
Originality/value
The paper presents a conceptual basis of how CC enables structural flexibility of SCs through easy, real-time resource and capacity reconfiguration. CC not only reduces cost and increases flexibility but also offers an effective solution for disruptive new business models with the potential to revolutionise current SCM thinking.
We present recent progress on the development of a new fully nonlinear potential flow (FNPF) model for estimation of nonlinear wave-body interactions based on a stabilized unstructured spectral element method (SEM). We introduce new proof-of-concepts for forced nonlinear wave-body interaction in two spatial dimensions to establish the methodology in the SEM setting utilizing dynamically adapted unstructured meshes. The numerical method behind the proposed methodology is described in some detail and numerical experiments on the forced motion of (i) surface piercing and (ii) submerged bodies are presented.
Taking concrete steps towards a carbon-free society, the Danish Parliament has recently approved the establishment of the world's first two offshore energy hubs on Bornholm and on an artificial island in the North Sea. Being the two first-of-their-kind projects, several aspects related to the inclusion of these “energy islands” in the current market setup are still under discussion. To this end, this paper presents a first large-scale impact analysis of offshore hubs on the whole European power system and electricity market. Our study shows that energy hubs in the North Sea contribute to increase social welfare in Europe. However, when considering the impact on each country, benefits are not shared equally. To help the development of such projects, we focus on the identification of the challenges arising from the hubs. From a market perspective, we show how exporting countries are affected by the lower electricity prices and we point at heterogeneous consequences induced by new transmission capacity installed in the North Sea. From a system point of view, we show how the large amount of wind energy stresses conventional generators, which are required to become more flexible, and national grids, which cannot always accommodate large imports from the hubs.
In 2017, Energinet and TenneT, the Danish and Dutch Transmission System Operators (TSOs), have announced the North Sea Wind Power Hub (NSWPH) project. The project aims at increasing by 36 GW the North Sea offshore wind capacity, with an artificial island collecting all the power produced by wind turbines and several HVDC links transmitting this power to the onshore grids. This project brings together new opportunities and new challenges, both from a technical and economic point of view. In this regard, this paper presents three analyses regarding the design and operation of such an offshore system. First, we perform a techno-economic assessment of different grid configurations for the collection of the power produced by wind farms and its transmission to the hub. In this analysis, two frequencies and two voltage levels for the operation of the offshore grid are investigated. Our findings show that the nominal-frequency high-voltage option is the more suitable, as lowfrequency does not bring any advantage and low-voltage would results in higher costs. The second analysis is related to the differences in operating the system with low- or zero-inertia; different dynamic studies are performed for each configuration to identify proper control actions and their stability properties. Comparing the outcomes of the simulations, we observed that voltage and frequency oscillations are better damped in the zero-inertia system; however, the risk of propagating offshore faults in the connected onshore grids is mitigated with the inclusion of the synchronous condensers. Lastly, a comparison of ElectroMagnetic Transient (EMT) and phasor-mode (also known as RMS) models is presented, in order to understand their appropriateness of simulating low- and zeroinertia systems. The results show that phasor approximation modelling can be used, as long as eigen-frequencies in power network are well damped.