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Main advantages and challenges of using Domain-Decomposition (DD) strategies for marine applications are examined. Splitting algorithms are discussed with emphasis on the spatial DD. Examples are given for platform and ship problems in connection with bottom-slamming and green-water occurrence. Features of the involved DD strategies are described and relevant verification and validation studies reported.

Marilena Greco is professor at Department of Marine hydrodynamics at NTNU

Oscillating boundary layers in the ocean are of fundamental interest as they are important in phenomena such as mixing, sediment transport and drift mechanisms. These boundary layers occur on different time and length scales. The waves induce a thin layer near the surface, and, for intermediate and shallow water depths, an oscillatory bottom boundary layer. The gravity forces from the moon and the sun, in conjunction with the Earths rotation, induces tidal boundary layers. Oscillatory boundary layers often result from an interaction between the oscillatory motion and a current, for example induced by wind at the ocean surface. In general these boundary layers are turbulent in the ocean, and it will be shown how these boundary layers can be calculated using a relative simple two-equation turbulence model. Results from an ongoing work considering the entire water column for a tidal flow with wind at the surface will be given. Finally a few preliminary LES test results from channel flow, from our development of LES codes, will be presented, and a brief discussion of some problems which we expect to face when using these models on geophysical flows will be given.

Lars Erik Holmedal is researcher at Department of Marine Technology, NTNU

Sivilingeniør Fredrik Bernhard Stabell ved Farmasøytisk institutt vil forsvare sin avhandling for graden dr.philos. (doctor philosophiae): Group II introns in the Bacillus cereus group with unusual splicing properties

Fredagskollokvium

Fredagskollokvium

Computer simulation is a powerful tool, which utilizes the power of computers in order to support and enforce the creativity of structural engineers. Although it is frequently used in research and development its potential for civil engineering practice has not yet been fully exploited. This is in part due to a lack of appropriate software tools well suited for this purpose. The author is involved in development of the software ATENA, which is aimed to bridge this gap. Theoretical background, solution methods and algorithmic solutions will be briefly described and validations of the models by experiments will be shown. The presentation will focus on numerous examples form engineering practice ranging from small (fastenings to concrete) to large structures (highway bridge, nuclear power plant containment). It will be shown that numerical simulation is becoming a powerful tool for solution of demanding problems of existing as well as new constructions.

Dr. Cervenka is the founder of the company Cervenka Consulting in Prague, Czech Republic. He is an internationally recognized expert in the field of mechanics of concrete structures and author of many scientific publications. His PhD thesis (University of Colorado, USA, 1970) on the topic of "Inelastic Finite Element Analysis of Reinforced Concrete Panels under In-Plane Loads", was a major contribution to the development of numerical models of concrete structures. He is recipient of numerous awards: Alexander von Humboldt research fellowship in Germany, Kajima foundation in Japan, Fellow of the Czech Engineering Academy, University of Colorado Distinguished Engineering Alumnus, and others. At present his main activity is in research and consulting in the field of concrete structures.

Fredagskollokvium

Fredagskollokvium

Fredagskollokvium

Fredagskollokvium

Fredagskollokvium

Environmental challenges related to hydrocarbon-based energy sources as well as resource constraints are the driving forces behind the R&D focus of StatoilHydro. In this presentation we will discuss availability of hydrocarbon energy sources and global energy demand. We will show how this motivates the research focus of StatoilHydro.

Ruben Schulkes is Chief Researcher Production Technology at StatoilHydro, Research Centre Porsgrunn, and is Professor II at the Mechanics Division

Cand Pharm Astrid Gjelstad ved Farmasøytisk institutt vil forsvare sin avhandling for graden ph.d. (philosophiae doctor): Development of electromembrane extraction - a new principle for rapid isolation and enrichment of ionic drugs

Fredagskollokvium

Fredagskollokvium

The mixing of temperature and pollutants in the ocean can be studied by examining how pairs of particles, deployed together, separate in time and space. Here we consider a recent field experiment in which 120 satellite-tracked surface drifters were deployed in pairs and triplets off the Norwegian coast. We discuss the observed dispersion, and how this can be rationalized within the framework of the theory of two-dimensional turbulence.

Joseph Lacasce is professor at the Department of Geosciences

Fredagskollokvium

Recent efforts to investigate a possible increased lifetime of old platforms have brought attention to some challenging hydrodynamic problems. Due to higher extreme waves and subsidence of seabed some of these platforms have become vulnerable to wave crests hitting the deck of the platform. Higher estimates of extreme wave crests may be due to better understanding of non-linear wave effects as well as including the uncertainty related to possible climate change effects. Due to complexity of deck geometry, CFD has been found necessary to predict wave impact loads. Numerical procedures to estimate extreme wave crests, obtain corresponding fluid particle kinematics and calculate impact loads will be presented.

Jørn Birknes is scientist at Det Norske Veritas

Fredagskollokvium

The word seismology is often associated with earthquakes. However, the tightly related term ``seismic'' comprises a valuable technology used extensively by the oil and gas industry in its exploration, development, and reservoir management operations. This talk will explain how marine seismic operations are carried out, and highlight some technological challenges that are faced. Special attention will be given to a factors like wave motion and turbulence, that add complexities to the operational environment. Such factors are challenging to handle from both a fluid dynamical and a signal-processing perspective.

Thomas Elboth is geophysicist at Fugro-Geoteam AS

Fredagskollokvium

The slow growth of a crack in windshield represents a mechano-chemical process: The stress at the tip of the fracture is not high enough to cause rapid fracture motion. Instead, fracture motion is determined by the diffusion of hydrogen to the crack tip, where it weakens the material, leading to crack tip propagation. The velocity of the fracture depends on the coupling between deformation, transport, and reactions. Similar coupled processes determine the rate of many reaction processes of geological relevance, such as weathering and carbonation during mineralogical CO2 sequestration. We have developed numerical model that allow us to address mechano-chemical processes during fluid infiltration. The model demonstrates that fracturing assisted reaction fronts in shrinking materials propagate with a constant velocity and width, and that the reaction rate in volume increasing reactions may be accelerated by feedback processes between fluid flow, mechanical deformation, and reactions.

Anders Malthe-Sørenssen is professor at the Department of Physics, working at the center for Physics of Geological Processes

Fredagskollokvium