Guest lectures and seminars - Page 201
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
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.