A New Approach to the Design of Mono-Hull FPSOs

2005 ◽  
Author(s):  
Tek Khaw ◽  
Phil Rawstron ◽  
Kaj Lagstrom
Keyword(s):  
Environmental Conditions ◽  
Rational Approach ◽  
Preliminary Design ◽  
Financial Loss ◽  
New Approach ◽  
Ship Building ◽  
Mass Properties ◽  
Current Design ◽  
Motion Performance ◽  
Fabrication Costs

Problems and issues arising in the design and operation of mono-hull FPSOs have been apparent for many years. This has resulted in shortcomings of current design philosophy being highlighted. Environmental downtime of 10 to 14 days per year is not uncommon in both new-built and converted FPSOs. The financial loss resulting from this downtime during the life of a field, is a significant factor in the overall field economics. The importance of selecting the principal dimensions of the hull to optimise the natural periods of the FPSO is discussed in this paper. Converted FPSOs are therefore at a disadvantage as the natural periods are already set by the principal dimensions and mass properties, which may not suit the environmental conditions at site, potentially resulting in high downtime. However, it is also noted that preliminary design of new built-FPSOs has also tended to neglect this aspect of design and opportunities to optimise motion performance have often been lost by following standard ship building practices in selecting initial principal hull dimensions. This paper explores a new rational approach to the design of the FPSOs, relative to the field environmental conditions, particularly for deep water locations. The main objective is to achieve minimum downtime to avoid financial penalties caused by the associated loss of production. Preliminary hull sizing software for optimising the hull principal dimensions, relative to the mooring and riser requirements and the field environmental conditions for a given storage capacity and topside load is presented. Benefits for the riser and mooring systems and for hull material and fabrication costs are also outlined.

scholarly journals Quasi-two-dimensional approximation for numerical simulation of flows in engine ducts

2019 ◽  
Author(s):  
V. Vlasenko ◽  
A. Shiryaeva
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Three Dimensional ◽  
Preliminary Design ◽  
Two Dimensional ◽  
Combustion Chambers ◽  
New Approach ◽  
One Dimensional ◽  
Dimensional Approximation ◽  
3D Flows

New quasi-two-dimensional (2.5D) approach to description of three-dimensional (3D) flows in ducts is proposed. It generalizes quasi-one-dimensional (quasi-1D, 1.5D) theories. Calculations are performed in the (x; y) plane, but variable width of duct in the z direction is taken into account. Derivation of 2.5D approximation equations is given. Tests for verification of 2.5D calculations are proposed. Parametrical 2.5D calculations of flow with hydrogen combustion in an elliptical combustor of a high-speed aircraft, investigated within HEXAFLY-INT international project, are described. Optimal scheme of fuel injection is found and explained. For one regime, 2.5D and 3D calculations are compared. The new approach is recommended for use during preliminary design of combustion chambers.

scholarly journals Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters

2007 ◽  
Vol 14 (3) ◽  
pp. 21-26 ◽  
Author(s):  
Tomasz Cepowski
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Ship Design ◽  
Design Parameters ◽  
Preliminary Design ◽  
Operational Effectiveness ◽  
Design Problems ◽  
New Approach ◽  
Analytical Functions ◽  
Effectiveness Index

Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters This paper presents a new approach which makes it possible to take into account seakeeping qualities of ship in the preliminary stage of its design. The presented concept is based on representing ship's behaviour in waves by means of the so called operational effectiveness index. Presented values of the index were calculated for a broad range of design parameters. On this basis were elaborated analytical functions which approximate the index depending on ship design parameters. Also, example approximations of the index calculated by using artificial neural networks, are attached. The presented approach may find application to ship preliminary design problems as well as in ship service stage to assess sea-keeping performance of a ship before its departure to sea.

Development of System for High Quality Wood Grain Design

2011 ◽  
Author(s):  
Takuya Mori ◽  
Satoshi Shibasaki ◽  
Hideki Aoyama
Keyword(s):  
Computer Graphics ◽  
Tree Growth ◽  
Wood Surface ◽  
Environmental Conditions ◽  
Tree Species ◽  
Growth Conditions ◽  
High Quality ◽  
New Approach ◽  
Conventional Methods ◽  
Wood Grain

Various approaches for generating woodgrain patterns using computer graphics have been proposed so far. However, it is difficult to reproduce real woodgrain patterns using such conventional methods. In this paper, a new approach for generating woodgrain patterns is proposed. Virtual trees are generated by simulating tree growth in consideration of environmental conditions. Moreover, fine tree tissues and reflection properties at the wood surface are modeled. By applying these modeled factors, more diverse and accurate woodgrain patterns can be generated. With this approach, various types of virtual trees can be obtained by changing growth conditions such as period and location of growth or form of tissue in trees without the need to reset complicated parameters of each tree species. After this, the virtual trees can be cut at arbitrary areas, thus allowing a variety of woodgrain patterns to be generated by easy parameter setup.

Self-Assembling Nanostructures: Recognition and Ordered Assembly in Protein-Based Materials

1992 ◽  
Vol 292 ◽  
Author(s):  
Kevin P. McGrath ◽  
David L. Kaplan
Keyword(s):  
De Novo ◽  
Specific Interaction ◽  
Rational Approach ◽  
New Approach ◽  
Consensus Sequences ◽  
Specific Recognition ◽  
Self Assembling ◽  
Biological Recognition ◽  
Recognition Elements ◽  
Recombinant Polypeptides

AbstractA new approach to materials design is presented, utilizing specific recognition and assembly at the molecular level. The approach described exploits the control over polymer chain microstructure afforded by biosynthesis to produce proteinbased materials with precisely defined physical properties. Incorporated into these materials are recognition elements that stringently control the placement and organization of each chain within higher order superstructures. The proteins, designated Recognin A2 through Recognin E2, are recombinant polypeptides designed de novo from both natural consensus sequences and an appreciation of the physical principles governing biological recognition. These materials are designed to examine the forces involved in specific recognition and complexation. through control of charge identity and placement, a pattern for specific interaction can be introduced. A subset of these materials are programmed to spontaneously assemble into complex, multicomponent structures and represent the first step in a rational approach to nanometer-scale structural design.

scholarly journals Phronetic Ethics in Social Robotics: A New Approach to Building Ethical Robots

2020 ◽  
Vol 63 (1) ◽  
pp. 165-183
Author(s):  
Paweł Polak ◽  
Roman Krzanowski
Keyword(s):  
Autonomous Robots ◽  
Social Robotics ◽  
High Level Architecture ◽  
Ceteris Paribus ◽  
New Approach ◽  
Moral Agents ◽  
Current Design ◽  
Human Ethics ◽  
High Level

Abstract Social robotics are autonomous robots or Artificial Moral Agents (AMA), that will interact respect and embody human ethical values. However, the conceptual and practical problems of building such systems have not yet been resolved, playing a role of significant challenge for computational modeling. It seems that the lack of success in constructing robots, ceteris paribus, is due to the conceptual and algorithmic limitations of the current design of ethical robots. This paper proposes a new approach for developing ethical capacities in robotic systems, one based on the concept of Aristotelian phronesis. Phronesis in principle reflexes closer human ethics than the ethical paradigms we employ today in ethical robotics. This paper describes the essential features of phronesis and proposes a high-level architecture for implementing phronetic principles in autonomous robots. Phronetic robotics is in its early stages of conceptualization, so many of the presented ideas are speculative and require further research.2

scholarly journals An Intelligent/Learning Axial Fan Design System

1991 ◽  
Author(s):  
Dennis G. Jackson ◽  
Terry Wright
Keyword(s):  
Design Process ◽  
Design Parameters ◽  
Design System ◽  
Preliminary Design ◽  
Axial Fan ◽  
Design Program ◽  
Current Design ◽  
Computer Based ◽  
Refinement Process ◽  
Blade Element

A computer-based axial fan design system has been developed that allows the designer to rapidly obtain a preliminary axial fan design. Program FANDES allows the designer two options to determine the preliminary design parameters for a single-stage axial fan. The first option allows the designer the ability to design an axial fan using conventional blade-element design techniques. The second option enables the designer to search a database of previously designed fans for a set of scaled fans that will satisfy the current design point requirements. The designer can then refine one of the fans in this set to possibly improve the selected fan’s performance. The database of fans is utilized and maintained by FANDES and new fans are added at the user’s request. This allows for an intelligent program that is constantly learning from previous designs. As more fans are designed and saved to the database the design process becomes more of a selection and refinement process of previously designed fans.

scholarly journals Mind-Shift: An Method for Power and Energy Reduction inApplication Mapping onto Network-o-Chip architectures

2021 ◽  
Author(s):  
yasin asadi
Keyword(s):  
Efficient Design ◽  
Improved Method ◽  
New Approach ◽  
Current Design ◽  
One Step ◽  
Ip Cores ◽  
Iot Devices ◽  
On Chip ◽  
Power And Energy ◽  
Designing Method

Abstract Network-on-chip (NoC) is an efficient interconnection designing method for solving the limitations of buses in connecting IP cores. Power consumption is one of the most important issues in this area, solving this problem can lead to a more reliable and efficient design of NoC. Besides, there is another problem which is the More’s law is reaching an end. In this paper, we used a new approach, which improves designing points, so we can design NoC architecture more efficiently based on previous designs. Briefly, this method adds one step before the overall change of architecture which tests if the current design can be improved if we change some internal characteristics. For validation, we applied this method by using wire NoC, and changing its bottlenecks, and make them more efficient by using mapping and adding antennas for wireless communication. While this method seems simple at the first sight, but the result can help many designing, which are vital for industries, and technologies like Wireless Sensor Networks (WSN) and Internet of Things (IoT) devices. Briefly, this method can be used in NoC architectures and make them more efficient in a new style for new purposes. The results compared with the basic designing method with the new improved method; power and Energy improvements are respectively 25% and 46% with mapping and wireless improvements and approximately 60% more than traditional NoC in comparison with the basic method in this approach. This method also paves the way for green computing by avoiding producing more chemicals and products from a reusability perspective.

Improving the Installation Criterion for Concrete Coated Pipelines

2018 ◽  
Author(s):  
Ngoc Nguyen ◽  
Olav Fyrileiv ◽  
Chor Yew Chia
Keyword(s):  
Numerical Model ◽  
Rational Design ◽  
Phase 1 ◽  
Design Criterion ◽  
Rational Approach ◽  
Operation Conditions ◽  
Steel Material ◽  
Current Design ◽  
Applicable Range ◽  
Concrete Strain

Current design practice limits the concrete strain to approximately 0.2% in a simplified design criterion. In most standard cases, this has proved to be safe and adequate. However, in recent years, the pipeline industry is extending into more remote, harsher environments and larger diameter pipelines. The use of the simplified design criterion has, in some circumstances, resulted in too strict installation requirements which limit the number of relevant installation vessels. This paper presents some findings on the concrete strain for submarine pipelines with concrete weight coating (CWC) derived from the numerical program performed within the scope of Phase 1 of the joint industry project “Design of concrete coating for submarine pipelines”. Non-linearities in the concrete weight coating, anti-corrosion coating (ACC) and steel material properties, as well as large deformation and the sequence of load application were included in the numerical model. The results from the numerical analyses have been well validated against existing experimental data, and the numerical model was subsequently used in an extensive parametric study, where the behaviour of concrete coated pipelines was investigated for monotonic and reversed bending with nominal strain up to 0.4%. These numerical results can be used to widen the applicable range of the simplified concrete crushing criterion in DNVGL-ST-F101 (2017), and to formulate a rational approach for the design of pipeline concrete weight coating under typical installation and operation conditions. The rational design approach will allow for a wider range of installation vessels to select from for installation of the pipeline, and relaxation of the installation weather window criterion.

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