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ABSTRACT Rapid Prototyping Technology is a group of manufacturing processes that enable the direct physical realization of 3D computer models. This technology converts the 3D computer data provided by a dedicated file format directly to a physical model, layer by layer with a high degree of accuracy. This technology is fast developing and is more than competitive to traditional model building techniques considering time and degree of detail. The paper gives an overview on existing major RP techniques and their applications, aiming to show the potentials to the offshore engineering community. INTRODUCTION Rapid Prototyping Technologies and Rapid Manufacturing offer great potential to offshore technologists and marine researchers with the focus on enlarging the view to other ways for producing models and unique parts for the expensive equipment necessary in investigating yet unknown worlds. Thus, the reliability of products can be increased; investment of time and money is less risky. Not everything that is thinkable today is already workable or available at a reasonable price, but this technology is fast evolving and the better the challenges, the better for this developing process. OVERVIEW Rapid Prototyping Technology (RPT), Solid Freeform Fabrication (SFF) or Layer Manufacturing encompasses a group of production processes that started emerging at the end of the 80s/Fritz, 2001/. Unlike conventional production processes, which work in a subtractive manner (removing material from a raw block of material giving the final shape of the part), the RPT process builds up parts layer by layer. The CAD representation should be done using a 3D solid modeler. These CAD data are derived either from the design process, from a 3D measuring device's point cloud or from computer tomography (CT). Most 3D solid modelers offer an interface to the STL file format that is used as input into the RP machines.
- North America > United States (0.47)
- Europe > Germany (0.29)
- Materials (0.69)
- Health & Medicine (0.50)
- Government (0.48)
- Aerospace & Defense (0.47)
Useful Force Models For Simulation of Multibody Offshore Marine Operations
Reinholdtsen, Svein-Arne (Norwegian Marine Technology Research Institute AS (MARINTEK)) | Mo, Knut (Norwegian Marine Technology Research Institute AS (MARINTEK)) | Sandvik, Peter C. (Norwegian Marine Technology Research Institute AS (MARINTEK))
ABSTRACT This paper presents some useful numerical force models for simulation of multibody offshore marine operations. The models cover pairs of docking funnels and docking posts, bumper elements and fenders. A method for including time-varying mass is also covered. The models are demonstrated through simulation studies. The purpose of the paper is to demonstrate how marine operations can be analysed. INTRODUCTION Increasingly complex combinations of floaters, suspended loads, slender structures and underwater robotic tools are expected during many future marine operations offshore. Accurate software tools for design of offshore marine operations will become increasingly more important for all-year activities related to the oil and gas fields that move into deeper water. These tools can increase the ability to conduct safe and efficient installations, inspections and interventions of the installations in the ocean space. A pair of a docking funnel and a docking post is a device assisting during the final precision manoeuvre before landing or connection of a structure to a fixed point on a body or on the seabed. These devices are arranged in pairs (guide funnel and guide posts or docking cone/cylinder and guide pin). Deflectors/bumper bars are used to guide a module to its correct position and to protect existing equipment from impact damages. The Bumper elements can be applied for global positioning of a body, or as a contact element between bodies. Fenders are utilized for different vessel-to-vessel operations, vessel-todock and vessel-to-fixed structure applications, particularly in exposed locations and areas where abrasion resistance is an important factor. A fender is here defined as a contact element, either between a body and a globally fixed point, or between two bodies. Compressive forces parallel to the normal vector of a sliding plane and friction forces along the sliding plane are the important forces in the fender model.
Deep Sea Unmanned Underwater Vehicles In JAMSTEC
Aoki, Taro (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Tsukioka, Satoshi (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Murashima, Takashi (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Yoshida, Hiroshi (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Nakajoh, Hidehiko (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Hyakudome, Tadahiro (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Ishibashi, Shoujirou (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)) | Sasamoto, Ryoko (Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC))
ABSTRACT Japanese islands stand on the edge of the deep trenches. It is famous that the Pacific Plate is slipping under the Eurasia one, and there are many earthquakes around Japan. It is serious that big earthquakes will come in the near future. And, there are concerns about the impact global warming will have to our environment, and which will inevitably result in expanding deserts and rising water levels. To gain detailed maps of deep underwater floors and a better understanding of global warming, JAMSTEC has begun to conduct research to clarify the mechanisms of them. Wanting the research to be carried out as effectively as possible, AUVs were considered and chosen, as the most suitable for these tasks. JAMSTEC started building the long cruising AUV "URASHIMA", the marine robot "MR-X1", and the deep ROV "UROV7K". INTRODUCTION Since the establishment of JAMSTEC in 1971, several basic and advanced survey systems have been developed to exploit and study the deep ocean. However, many areas still remain unexplored such that ice covered seas, stormy and rough seas, around active ocean volcanoes and other dangerous areas. The problems of global scales such as global environmental problem, natural disaster, energy resource problem is closely related to the ocean, and it is necessary to research of these unexplored sea areas for the solution. For this purpose, JAMSTEC tries to not only improve the present research systems and observation instruments, but also research and develop new technologies and equipment for wider observation sea areas. Cruising AUV "URASHIMA" "URASHIMA" Project The planned development of the JAMSTEC AUV consists of two stages. Following "URASHIMA", the second stage is the development of "URASHIMA-2" (Fig.2), which will have the ability to achieve a depth of 6,000m and cruising range of 5,000km.
- North America > United States (0.28)
- Asia > Japan (0.25)
- Energy > Energy Storage (1.00)
- Electrical Industrial Apparatus (1.00)
ABSTRACT With Petro-Canada's extensive involvement in oil and gas development off Canada's East Coast, the company made a strategic decision to establish and locate a new Strategic Business Unit (SBU) in eastern Canada to manage all of its East Coast offshore development and operations activities. This entity has established itself firmly as a major player in Canada's East Coast offshore oil and gas industry. With the establishment of the East Coast SBU, Petro-Canada East Coast management believed that real value was to be gained in designing and implementing a dedicated, structured Quality Management System with the objective being to help effectively manage its East Coast activities and to continually improve the quality of work. This paper outlines the main features of Petro-Canada East Coast's Quality Management System. INTRODUCTION Petro-Canada is a major player off Canada's East Coast (Figure. 1) with interests in every major Grand Banks discovery to date. The company holds significant interests in the Hibernia field (the first Grand Banks development) which has been producing oil since 1997, and is the operator of the Terra Nova field development which achieved first oil early in 2002. It also holds interests in the White Rose development, which is currently in project phase, and in the Hebron/Ben Nevis discovery. Outside the Grand Banks, Petro-Canada is executing a 2003 exploratory drilling program in the Flemish Pass Basin (deepwater) and also has extensive land position in both explored and under-explored regions off Newfoundland and Nova Scotia. With the establishment of the Petro-Canada East Coast Strategic Business Unit in the late 1990's, Petro-Canada East Coast management believed that real value was to be gained in designing and implementing a dedicated, structured Quality Management System with the objective being to help effectively manage its East Coast activities and to continually improve the quality of work.
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean > Atlantic Margin Basin > Grand Banks Basin > Jeanne d'Arc Basin > Terra Nova Field (0.99)
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean > Atlantic Margin Basin > Grand Banks Basin > Jeanne d'Arc Basin > Hibernia Field > Hibernia Formation (0.99)
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean > Atlantic Margin Basin > Grand Banks Basin > Jeanne d'Arc Basin > Hibernia Field > Avalon Formation (0.99)
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean > Atlantic Margin Basin > Grand Banks Basin > Flemish Pass Basin (0.99)
Victor 6000: Design, Utilization And First Improvements
Michel, Jean-Louis (Ifremer, Centre de Méditerranée, Département Systèmes Sous-Marins de la DNIS) | Klages, Michaël (Alfred Wegener Institute for Polar and Marine Research) | Barriga, Fernando J.A.S. (Departamento de Geologia, Faculdade de Ciências de Lisboa) | Fouquet, Yves (Ifremer, Département Géosciences Marines de la DRO) | Sibuet, Myriam (Ifremer, Département Environnement Profond de la DRO) | Sarradin, Pierre-Marie (Ifremer, Département Environnement Profond de la DRO) | Siméoni, Patrick (Ifremer, Département Systèmes Sous-Marins de la DNIS) | Drogou, Jean-François (Ifremer, Département Systèmes Sous-Marins de la DNIS)
ABSTRACT Following the needs of a widening community of end users the modular deep Remotely Operated Vehicle Victor 6000 of the Institut Français d'Exploitation de la Mer, Ifremer, is evolving using new technologies. A deep record dive at high latitude (79°north) was reached in the Molloy Deep at 5550 metres in 1999. The performance obtained till 2002 during 2600 hours of work/survey near the seafloor are contributing significantly to the observation and the monitoring of the deep benthic ecosystems in various environments of the midoceanic ridges and the continental margins. INTRODUCTION The purpose of this paper is to give technical and scientific background leading to the successful operation and results of the 6000-m depth-rated Remotely Operated Vehicle (ROV), Victor 6000, during the past 4 years. The industrial and technical context, that favored the development by Ifremer of a ROV dedicated to scientific users, is summarized. Those experiences conduct to list and select new improvements to take into account reliability and operability improvements, obsolescence, new ideas and requirements, several of them being allowed or caused by the technical progress. Some perspectives are defined before the conclusion. THE VICTOR 6000 DEVELOPMENT In the 90s the offshore oil industry increased its use of large, work class ROV, with depth capacities evolving from 1000 to 3000 meters at the end of this decade. Following these evaluations and a feasibility study, the Ifremer decided to invest in the development of a ROV dedicated to the scientific utilization in coherence with the 6000-metre depth capabilities of the Ifremer deep-sea fleet. The former accrued experiences in deep-sea technologies, developed and operated on the manned submersibles (Nautile/Robin and Cyana) as on several towed vehicles and robots (Epaulard, Sar, Scampi), made Ifremer sub-sea systems designers able to take in charge this development.
- North America > United States (1.00)
- Europe (1.00)
- Geology > Geological Subdiscipline (1.00)
- Geology > Structural Geology > Tectonics > Plate Tectonics (0.87)
- Electrical Industrial Apparatus (1.00)
- Energy > Oil & Gas > Upstream (0.66)
- North America > United States > Alabama > Molloy Field (0.98)
- North America > Canada > Alberta > French Field > Arl French 16-26-64-1 Well (0.98)
- Europe > Norway > North Sea > Northern North Sea > North Viking Graben > Troll Area > Block 35/11 > Fram Norway Field > Sognefjord Formation (0.97)
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ABSTRACT This paper sums up the background and motivation for developing international pipeline codes i.e. basically the new ISO 13623 and the DNV-OS-F101 Pipeline Standards. The recent developments that have taken place are focused. Basic aspects of pipeline code development are discussed on a general basis as are the various aspects of selecting the appropriate code in a specific case. The experiences made in international use of these codes are discussed on the basis of some major pipeline projects where these codes have been applied. The discussion aims at coming up with answers to questions like: Did the codes meet the expectations as to international acceptance? To what extent have they been taken into use? Is there an optimum code to be selected for a pipeline project? The impact by the new pipeline codes on pipeline integrity management is discussed on a general basis. INTRODUCTION Pipelines are effective and highly reliable means for hydrocarbon transportation over short and medium range distances and are being built over longer distances and in deeper waters. They represent a large investment cost and will normally constitute a major part of the total cost for a hydrocarbon field development. These investment costs are influenced by the applicable codes for design and construction of the pipeline. Hence, an effective optimisation of the pipeline costs versus pipeline reliability will always be highly relevant. Fig. 1 shows a general economy comparison between different transportation means. The split between the different alternatives are naturally depending on the degree of optimisation and innovation. Even though pipelines are the biggest investment of a hydrocarbon development infrastructure, the contribution to the over all pipeline cost varies significantly depending on the pipeline. For shorter pipelines, flow-lines, the installation and fabrication cost or the operational cost may be the major cost contributor.
- North America > United States (0.94)
- Europe > Norway (0.69)
New Design Criteria of Coastal Engineering For Disaster Prevention
Dong, Sheng (College of Engineering, Ocean University of China) | Wei, Yong (Department of Ocean and Resource Engineering, University of Hawaii at Manoa) | Li, Feng (College of Engineering, Ocean University of China) | Liu, Defu (College of Engineering, Ocean University of China)
ABSTRACT Compared with traditional one-dimensional extreme value statistical method, the new design criteria are put forward based on joint probability theory for structural design. The proposed procedure considers the combined effect of storm surge, large waves and winds impacting on coastal structures. Because it is difficult to solve the joint probability of non-Gaussian correlated multivariate distribution, Importance Sampling Procedure (ISP) is utilized to solve this problem. Results show that ISP is a simulating technique with advantages of advance, high efficiency and fast convergence. The design criteria are also given out for engineering construction in coastal zone of Qingdao. INTRODUCTION The coastal cities are mostly regional economic development centers in China. Frequently typhoon attacking and associated surge flooding cause heavy loss of lives and properties in these areas. The determination of the coastal engineering design criteria against natural disaster plays an important role in the sustainable development of coastal cities. For instance, Qingdao, a coastal city of east China, was severely flooded along the coastline in 1992 when typhoon-induced storm surge coincided with high tides and large waves. 26 lives were taken away and the properties damages were reported to be over 80 million dollars during this tragedy. In a general way, traditional design criteria for most coastal structures, which assume to be acted on by one single load, are established based on one-dimensional extreme value analysis. However, more rigorous approach is in need to take into consideration of the joint impacts from waves, tides and winds during a storm event. The loads induced by extreme storms are critical in the design of coastal disaster-prevention structures. The load arises from a combination of waves, tidal levels and wind, though waves are generally the dominant factor. This topic has attracted many researchers' attention (Wen, 1991; Forristall et al, 1991; Tromans, 1995).
Analytical Approximation For Tidal Dynamics In Coastal Aquifers
Jeng, D.-S. (School of Engineering, Griffith University Gold Coast Campus) | Teo, H.T. (School of Engineering, Griffith University Gold Coast Campus) | Barry, D.A. (School of Engineering and Electronics, The University of Edinburgh) | Li, L. (School of Engineering, The University of Queensland)
ABSTRACT Recently, considerable effort has been devoted to the studies of watertable fluctuations in coastal aquifers. However, most previous investigations have been based on one-dimensional models that describe the processes in the cross-shore direction alone, assuming negligible alongshore variability. A recent study proposed a two-dimensional approximation for tide-induced water table fluctuations that took into account coastline variations. In this study, we further develop this approximation in two ways, by extending the approximation to second-order and by taking into account capillary effects. Our results demonstrate that both effects can markedly influence water table fluctuations. In particular, with the first-order approximation, the tide-induced water table fluctuations could be subject to sizable errors. INTRODUCTION Recently, considerable research effort has been devoted to water-table fluctuations in coastal aquifers. Tide-induced water table fluctuations in a sandy beach affect erosion (Duncan 1964), saltwater intrusion (Dagan and Zeitoun 1998), and biological activity (Pollock and Hummon 1971). Tide-driven fluctuations of the beach water table that decay landward from the shoreline are asymmetric and skewed in time, and have average levels higher than the mean sea level (Emery and Foster 1948; Isaacs and Bascom 1949; Lanyon et al. 1982). When the tide falls more rapidly than the beach drains, a seepage face forms, potentially affecting sediment transport (Turner 1993). Most previous investigations have been limited to one-dimension in the cross-shore direction, in which case the alongshore variability of the coastline cannot be examined (Li et al. 1997a, 1997b; Nielsen 1990; Nielsen and Perrochet 2000). Recently, researchers have considered the shape of the coastline through two-dimensional models. Among these, Sun (1997) developed a two-dimensional analytical solution for tidal fluctuation in aquifers adjacent to estuaries. However, the boundary condition in his model ignored the effects of oceanic tides, as pointed out by Li et al. (2000).
ABSTRACT Detailed measurements of pressure and scouring depth were performed to improve understanding of the influence of varied phenomena on the riverbed around the spur dike. Two sets of hydraulic conditions, 20 pressure-measuring points and scouring recorded during the surge combined together gave the image of how the liquefaction occurs around the structure. The liquefaction was found as a facilitating process during the scouring action. INTRODUCTION Spur dikes are seen as one of the best types of hydro-engineering structures for preserving the desired water depth or deflecting the main current in the harbor channel or river. This type of construction has been used for a long time in many cases in the river hydraulics as well as in the marine hydraulics, proving its usefulness and good features. In the sandy riverbeds, placement of every kind of structure results in scouring. This process poses a very serious danger for the stability of a structure. The primary target of the research is to develop better structures and improve understanding of the interaction between artificial structures and the natural environment. That is the reason why many researchers conducted experiments and analysis on flow model and scouring action around obstacles in water. Most of them focus on the scouring phenomenon (Sumer, 1994, 2001; Elawady, 2001; Rahman, 1998) the velocity profiles (Mia, 2002; Sumer, 1994; Elawady, 2000) near the structures. The scouring phenomenon is very important because of its crucial point in a structure's stability. The main parameter influencing the scouring process is shear stress caused by velocity. Because the velocity profiles are complicated and characterized by 3-dimensional particle movement, many researchers dealt with this topic. Different configurations of structures like spur dikes, bridge abutments, piles etc. were investigated which improved understanding of the complicated water flow around single and groups of obstacles.
- Asia > Japan (0.29)
- North America > United States (0.28)
- Research Report > New Finding (0.50)
- Research Report > Experimental Study (0.50)
On the Damping Coefficients of Sponge Layer In Boussinesq Equations
Hsu, Tai-Wen (Department of Hydraulic and Ocean Engineering, National Cheng Kung University) | Yang, Bin-Da (Department of Hydraulic and Ocean Engineering, National Cheng Kung University) | Tseng, I-Fan (Department of Hydraulic and Ocean Engineering, National Cheng Kung University) | Tsai, Jin-Yan (Department of Hydraulic and Ocean Engineering, National Cheng Kung University)
ABSTRACT The theoretical damping coefficients of the sponge layer are derived for Boussinesq equations. Numerical experiments show that the coefficients work efficiently to damp the energy of outgoing waves. The present result differs from former researches using empirical parameters to control the effect of the sponge layer. It is found that the values of damping coefficients increase with the increase of the relative water depth. The numerical results for wave propagating over a submerged bar bathymetry are fairly compared with experimental data. INTRODUCTION The prediction of wave transformation from deep water to shallow water is of great importance to an understanding of coastal processes. As waves propagate to nearshore, the wave form is modified by a combination of wave shoaling, refraction and diffraction. In the nearshore region, nonlinear effects become notable to induce wave energy transfer both up and down the spectrum that lead to the generation of low-frequency surf beats as well as high-frequency enhancements to the shoaling wave crests. Boussinesq equations are commonly used to provide an accurate description of wave evolution in coastal regions. These equations introduce a polynomial approximation of the vertical distribution of the flow field into the integral conservation laws of mass and momentum that include the effects of nonlinearity and frequency dispersion. The successes of corresponding research work (Madsen and Sørensen, 1992; Nwogu, 1993; Wei et al., 1995) were noted in comparisons between laboratory data and model predictions. More recently Gobbi and Kirby (1999), Gobbi et al. (2000) and Madsen et al. (2002) developed new approximations valid for highly dispersion and nonlinear waves. Although their Boussinesq equations significantly improve the nonlinearity and dispersion characteristics, the equations are too complicate to engineering practice. For a numerical model of Boussinesq equations, appropriate boundary conditions are needed to run the model properly