Green Liner Shipping Network Design refers to the problems in green logistics related to the design of maritime services in liner shipping with a focus on reducing the environmental impact. This chapter discusses how to more efficiently plan the vessel services with the use of mathematical optimization models. A brief introduction to the main characteristics of Liner Shipping Network Design is given, as well as the different variants and assumptions that can be considered when defining this problem. The chapter also includes an overview of the algorithms and approaches that have been presented in the literature to design such networks.
Traditionally, most ship hulls are optimized for ideal conditions, where the ships are sailing in calm water with full speed in full load. In the last decade, some ships have been designed for a range of draughts and speeds in calm water. However, there is still a large gap between the ideal conditions the ships are designed for and conditions (waves, wind, currents, hull roughness ets.) the ships will operate in. The target for the thesis is to develop accurate numerical models that can help ship designers narrow a part of this gap.
The main body of this thesis is three papers. The first papers compares the speed/power performance of full-scale CFD simulations, towing tank predictions, and high quality speed trial measurements from six sister vessels. Much research have been conducted comparing model- scale CFD with towing tank results. However, very few studies have compared full-scale CFD with speed trial measurements. The study includes both a ro-ro vessel and a general cargo vessel. The present study finds that including the hull and propeller roughness directly into the CFD simulations by modifying the wall-functions provides more accurate results than the traditional approach of estimating the effect of roughness using an empirical formula.
Today, most ships are designed for sailing in calm water. However, very few ships sail entirely in calm water. Before numerical simulations can be used to predict added resistance in waves and seakeeping responses, a systematic verification and validation is required to ensure the accuracy. The second paper presents such a systematic verification and validation for the KCS container ship in oblique waves. Five wave headings and six wavelengths are studied. The estimated spatial and temporal discretization errors are found by an extensive verification study to be less than 5 %. Results from the verified CFD model are compared with existing potential flow and CFD results from the literature, as well as up to three experimental data sets. The comparison shows that the present CFD results in general show significantly better agreement with the experiments than previously published CFD results.
This CFD set-up is used in the third paper to study how sailing in oblique regular waves influences the nominal wake field of the KCS ship. Five different headings are studied and the waves have a steepness of 1/60 and a wave length equal to the ship length. The present study finds that the studied incident waves make the nominal wake field highly transient. Especially the transient bilge vortex and shadow from the skeg have a significant influence on the nominal wake field. The results show that the nominal wake fraction fluctuates up to 39 % of the mean nominal wake fraction for the studied waves. The mean nominal wake fraction is higher than in calm water for all headings besides head sea waves. It is found that the stern quartering sea waves has the maximum mean nominal wake fraction, with a 16 % higher mean nominal wake fraction than in calm water. Finally the study finds that the modified advance angle on the r/R = 0.7 circle in the propeller plane varies 3.5 degrees more in stern quartering than in calm water. This increases the risk of cavitation leading to potential vibrations and loss of propulsive efficiency.
The three papers show that CFD simulations can deliver highly accuracy results, when the CFD simulations are set-up very carefully and systematic verification and validation are conducted. The results from the three papers shows that numerical simulations have a massive potential as useful tools when designing ships for the conditions, the ship will operate in.
In 2021 DS Norden celebrated its 150 years anniversary. In this book Martin Jes Iversen is analyzing the history of the shipping company which is one of the oldest in Denmark. In the first 50 years after being founded in 1871, Norden was a pioneer firm in Danish shipping. This period was followed by five decades of financial stability and gradual stagnation. But in the early 1990s the firm started its journey to become one of the leading firms in the global dry-bulk market. As the world experienced technological, economical and political changes, Norden would also change. Some of these changes were incremental. Others were more abrupt. But they were never predictable.
According to the narratives transmitted through media and political discourse, climate change reduces the ice coverage in the Arctic and enhances shipping and other forms of maritime activities. Especially, expectations of an increasing level of transit shipping between Asian, especially Chinese, ports and ports in Europe and North America is dominant. Evidence, however, tells that the numbers of transit shipping through the Arctic Ocean are very limited, and dominated by European shipping companies. For Greenland, political expectations have also been high, since Greenland has been seen as "strategically" situated in relation to new shipping routes in the Arctic, But, again, the actual development has been moderate and not related to international transits but conditions in Greenland itself.
In a new book, senior researcher Jessica Larsen analyses how relevant anti-piracy legislation was enforced when international ship contributions and regional coastal states cooperated on anti-piracy off the coast of Somalia in 2008-2016.
The book is a socio-legal study based on both clause analyses and ethnographic fieldwork. The book takes the reader on board a warship patrolling the Indian Ocean and into the courtrooms of the island nation of Seychelles, which conducted 17 piracy cases. Through interviews and observations, the book uncovers how anti-piracy legislation works in practice. Existing studies have primarily examined existing law. This book goes out into the field to also uncover applied law.
The analysis shows examples of ambiguity about which legal sources should be applied at sea. It identifies practices in court that show cases of impunity and questions legal certainty. The implications of this should be considered as counter-piracy off Somalia has been used as a model for counter-piracy elsewhere, such as in the Gulf of Guinea.
The report summarizes a major interview survey among freight forwarders, shipping companies and agents, as well as North Jutland customers of containerized sea transport.
This chapter is about emergent safety hazards in engineering systems. These
hazards are those that emerge from a system without arising from any part of the
system alone, but because of interactions between parts. We distinguish two
approaches to analysing engineering systems: one is to view them as sociotechnical, and the other is to consider them as cyber-physical systems. We
illustrate a great deal of emergent hazardous behaviours and phenomena due to
unknown accident physics, malign actions, chemistry, and biology and due to
deficiencies in managements and organisations. The method that follows the
socio-technical view consists in the representation of a system by sequential
functionally unrelated processes that can in reality influence the performance of each other via sneak paths. The method that follows the cyber-physical systems
view focuses on the analysis of control loops (feedback, feedforward, positive,
and negative) and, especially, interrelated loops. The chapter explores also the
realm of security threats due to malign actions that can trigger safety-threatening events. And finally it gives general guidance for avoiding and eliminating safety hazards when designing engineering systems.
Underwater radiated noise (URN) from ship propellers has attracted increasing interest in recent years due to its adverse environmental effects on marine life and their communication channels. The environmental concern to reduce shipping noise and the industrial requirements for faster computational tools are driving factors that promote research in the specialized domain of hydroacoustics. This thesis deals with the development of such a computationally efficient numerical tool, which can be used in the prediction of underwater radiated noise in the early design phase of propellers.
The numerical model is developed with two major objectives – versatility in assessing the relative contributions from the major propeller-noise generating mechanisms, and rapidity in prediction of overall noise behaviour. It uses the Farassat-1A solid-FWH formulation of the Ffowcs-Williams- Hawkings equation by defining equivalent acoustic sources on the propeller blade, sheet cavity and tip vortex cavity surfaces. In particular, the application of the solid-FWH formulation to the tip vortex cavity model is the major novelty in this thesis.
The hydrodynamic flow solution is obtained from a potential flow based solver ESPPRO, which includes analytical models of sheet cavitation and tip vortex cavitation. The hydroacoustic numerical model developed within this thesis, DoLPHiN, is a Python-based code that is primarily designed to accept input from ESPPRO; but during the research, the code has also been adapted to read input from the commercial, finite-volume-based Navier-Stokes solver, STAR-CCM+.
The numerical model implementations are verified through analytical case studies for simple geometrical shapes, such as a pulsating sphere and an oscillating cylindrical cavity. The verification study is further extended for propeller geometries by identifying approximate reference solutions in simplified operating conditions. The numerical tool is validated for industrial application through comparison of its noise prediction with model-scale and full-scale noise measurements. Specific characteristics of the propeller noise spectrum are identified in order to evaluate its noise prediction capabilities. The uncertainty factors involved when validating with experimental measurements are also explored in detail. Furthermore, a design study is presented, which shows potential use of the numerical tool in practical propeller design and optimization applications.