Ships And Sea Structures With A Hydrodynamic Perspective
O. M. Faltinsen
Centre for Autonomous Marine Operations and Systems (AMOS),
Department of Marine Technology, NTNU, NO-7491 Trondheim, Norway
There is a broad variety of ships and sea structures involved in transportation, oil and gas exploration and production, marine operations, recovery of oil-spill, renewable energy, infrastructure and aquaculture. Hydrodynamics by itself or in combination with structural mechanics and automatic control matters in design and operation. Ultra-deep and ultra-long structures with hydroelastic effects are parts of the scenarios. An example is floating bridges with a length up to about 4km intended for crossing fjords on the West Coast of Norway.
The expected increase in world population requires more food. There is a large potential in increasing the marine food production. There is a trend of moving marine fish farms to more exposed areas. The importance of marine technology will consequently increase. Renewable energy from waves, current and wind has continuing interest. Important issues are efficiency, survivability in extreme weather, site selection, energy cost and subsidies. Environmental concerns have led IMO (International Maritime Organization) to introduce an energy-efficiency-design index in terms of grams of CO2 emission per nautical mile divided by deadweight tonnage that applies to oil tankers, bulk carriers, gas carriers, general cargo, container ships, refrigerated cargo and combination carriers. High-speed ships are presently not so popular due to e.g. fuel consumption and CO2 emission. There is a tendency that activities repeat themselves with a period of the order of 30-40 years, then, adopting new advances in enabling technologies taking advantages of e.g. new materials, hybrid power plants (batteries, gas, diesel, renewables, etc.), guidance, navigation and motion control systems. Integrated design and analysis including hydrodynamics, structural mechanics and automatic control may open up for lighter and marginally dimensioned concepts.
Sloshing in LNG tanks, springing, and whipping as well as large-amplitude parametric roll of container vessels are examples on hot topics where ship hydrodynamics plays a dominant role. Springing of ships is wave-excited resonant global hydroelastic vibrations that matters for the fatigue life of large bulk carriers and container ships. Whipping is slamming-induced transient global ship vibrations. Sloshing-induced slamming in prismatic LNG tanks is a particularly complicated slamming problem because many fluid mechanic and thermodynamic parameters as well as hydroelasticity may matter. Furthermore, violent sloshing causes complicated in-flow scenarios of slamming. The consequence is that both computational tools and model tests are limited.
The Use of CFD in Design and Optimization of Maritime Structures
CD adapco Group, Nuremberg, Germany
Ships and offshore structures are exposed to sea currents, waves and wind. Design and optimization of such objects aims to maximize desirable and minimize undesirable effects, whereby the energy efficiency and safety for crew, cargo and environment play the major role. Computational fluid dynamics (CFD) is nowadays widely used to predict flow around and motion of floating objects, as well as interaction between flow and deformation of solid bodies. Recently special topics like cavitation and acoustics are also receiving increased attention.
The role of simulation in design and optimization of floating objects has significantly increased, due to developments of both computers and computing methods. While in the past computation was performed only for individual components (e.g. flow around hull, propeller, or rudder alone; structural analysis using assumed loads) using simplified methods (potential flow theory; beams for structures), it is nowadays possible to simulate realistic systems (e.g. coupled computation of water and air flow around ship with all appendages and geometrical details, and deformation of ship structure due to flow-induced loads) under real conditions (turbulent two-phase flow with waves).
The presentation will present advances in computational methods from the maritime standpoint, illustrated with practical examples from shipyards, research institutions and classification societies from all over the world, including trends for future development. Economic aspects of competitive advantage on the world market from an adequate use of simulation with the aim of improving the product quality while reducing the production cost will also be covered, as well as the interaction between simulation and experiment on the way to optimal products.
Opportunities For H2020 Projects Applications in the Maritime Sector
Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium
The lecture presents an insight in the currently ongoing H2020 European Commission program, with dedicated focus to the Maritime sector, with the objective to highlight the H2020 funding opportunities in the fields of naval architecture and marine engineering. It is well known that the European Commission does not treat shipbuilding as an independent sector in the â€śBlue Growth Opportunities for marine and maritime sustainable growthâ€ť strategy and roadmap. If we count all economic activities that depend on the sea, then the EU's blue economy represents 5.4 million jobs and a gross added value of just under â‚¬500 billion per year. In all, 75% of Europeâ€™s external trade and 37% of trade within the EU is seaborne. Much of this activity is concentrated around Europe's coasts, which is the driver of the economy because of their outward-looking geography, ports and coastal communities, which have been traditionally the centers for new ideas and innovation. In addition, to this traditional propensity for innovation, 3 new factors have come into play, due to:
1. Rapid technological progress in working offshore in ever-deeper waters. Robotics, video-surveillance and submersible technology are now routinely packaged into machinery for operations that were not feasible ten years ago.
2. Increase awareness that land and freshwater are finite resources. Further clearing of forests or draining of wetland will deprive future generations of the benefits they provide. We need to look how the 71% of the planet that is ocean can deliver human necessities such as food and energy in a way that is more sustainable. Meeting environmental targets can also be a source of innovation and growth.
3. Reduce greenhouse gas emissions has not only driven the deployment of offshore renewable energy installations, but has also provided a further impetus for energy saving and an additional reason to favor seaborne transport over land transport due to its lower emissions per tonne-kilometre. There is significant potential to reduce these emissions, which account for about 3% of the total greenhouse gas emissions by further improving the energy efficiency of ships.
As an example outreach, the European naval architecture and marine engineering need solutions to virtually design new generation ships with sophisticated software-hardware tools enriched with the multidisciplinary design optimization workflows, which involve variety of physical models and their respective simulations, tightly integrated through a highly-sophisticated visualization platform, in order to gain rapidly the virtual experience of the obtained results. Thus, enabling a highly trusted decision - to produce or not to produce - such new generation ships. It is expected that the authors' research experience, as put forward in this lecture, will possibly give contribution in triggering the advancement of such complex design tools and their applications, also in the fields of naval architecture and marine engineering.
Management of Ship Design and Engineering Business
Navis Consult d.o.o. - Rijeka, Part of Rolls Royce Group, Rijeka, Croatia
When ship design and engineering activity has to be organized as a successful business â€“ there are many challenges which have to be faced. Design and engineering is typically a creative and iterative process which is naturally not â€śbusiness friendlyâ€ť and does not easily meet a limited budget and time. The core of the process is the human resource - engineer. While the result of the process highly depends on the quality and development of human resource, the only way to achieve a successful business result is to manage all other factors which influence the process.
The global ship design market is divided into two segments : â€śhigh endâ€ť and â€ścommodityâ€ť market. The â€śhigh endâ€ť market includes highly complex ships where ship-owners pay attention to every detail of the ship construction and the definition of the quality of the ship depends not only on â€śglobalâ€ť ship performance but also on detail arrangements securing maintenance and safety for the crew. The â€ścommodityâ€ť market includes ships where ship-owners focus mainly on the ship price and â€śglobalâ€ť ship performance leaving the details to be solved in the relationship â€śsurveyorâ€“ builderâ€ť.
The presentation will show the specific method and approach developed for the management of a successful ship design and engineering company dealing with â€śhigh endâ€ť market â€“ complex ships for offshore technologies. It will also present a model of successful collaboration â€śacross borderâ€ť between two engineering communities in Croatia and Norway as a part of the leading international global company.