Blar i NTNU Open på forfatter "Ehlers, Sören"
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A method for estimation of equivalent-volume ice thickness based on WMO egg code in absence of ridging parameters
Milakovic, Aleksandar-Sasa; Schütz, Peter; Piehl, Henry Peter; Ehlers, Sören (Journal article; Peer reviewed, 2018)When calculating equivalent-volume ice thickness along a vessel's projected route for the purpose of ice resistance estimation, information on both undeformed ice (level ice) and deformed ice (mainly ridges) is needed. ... -
A simulation-based design method for arctic maritime transport systems
Bergström, Martin (Doctoral theses at NTNU;2017:93, Doctoral thesis, 2017)This thesis proposes a method for the conceptual design of arctic maritime transport solutions integrating the goal/risk-based regulatory system of the recently enforced International Code for Ships Operating in Polar ... -
An approach towards the design of robust arctic maritime transport systems
Bergström, Martin Vilhelm; Ehlers, Sören; Erikstad, Stein Ove (Maritime-Port Technology and Development;, Book; Chapter, 2014)This paper describes a simulation-based approach towards the design of robust arctic maritime transport systems that are adaptable to uncertain future ice conditions. It makes it possible to simulate the performance of ... -
An Object-Oriented Modeling Approach to Virtual Prototyping of Marine Operation Systems Based on Functional Mock-Up Interface Co-Simulation
Chu, Yingguang; Hatledal, Lars Ivar; Æsøy, Vilmar; Ehlers, Sören; Zhang, Houxiang (Journal article; Peer reviewed, 2018)This paper presents an object-oriented modeling (OOM) approach to model development of marine operation systems, specifically the hydraulic systems of marine cranes. Benefited from the rapid development of computation ... -
Assessment of structural requirements related to LNG fuel tanks
Aga, Halvor Larsson (Master thesis, 2013)This thesis considers collision between ships, and the structural resistance of the struckship with the aim to minimize the indentation into the ship side.First it gives a background in ship collision analysis, different ... -
Bowtie Analysis without Expert Acquisition for Safety Effect Assessments of Cooperative Intelligent Transport Systems
Ehlers, Ute; Ryeng, Eirin Olaussen; McCormack, Edward; Khan, Faisal; Ehlers, Sören (Journal article; Peer reviewed, 2018)Estimating the safety effects of emerging or future technology based on expert acquisitions is challenging because the accumulated judgment is at risk to be biased and imprecise. Therefore, this semiquantitative study is ... -
Current status and future operational models for transit shipping along the Northern Sea Route
Milakovic, Aleksandar-Sasa; Gunnarsson, Bjørn; Balmasov, Sergey; Hong, Sungwon; Kim, Kitae; Schütz, Peter; Ehlers, Sören (Journal article; Peer reviewed, 2018)The Northern Sea Route (NSR) has received increased international attention during the recent years as an alternative transit corridor for shipping between Europe and East Asia. In 2015, the project “Feasibility and ... -
Development of Combined Load Spectra for Offshore Structures Subjected to Wind, Wave, and Ice Loading
Braun, Moritz; Dörner, Alfons; Ter Veer, Kane F.; Willems, Tom; Seidel, Marc; Hendrikse, Hayo; Høyland, Knut Vilhelm; Fischer, Claas; Ehlers, Sören (Peer reviewed; Journal article, 2022)Fixed offshore wind turbines continue to be developed for high latitude areas where not only wind and wave loads need to be considered but also moving sea ice. Current rules and regulations for the design of fixed offshore ... -
Development of environmental contours for first-year ice ridge statistics
Chai, Wei; Leira, Bernt Johan; Næss, Arvid; Høyland, Knut Vilhelm; Ehlers, Sören (Peer reviewed; Journal article, 2020)Ice ridges represent a major threat to ships and offshore structures in areas with sea ice but no icebergs, since they frequently determine and govern the structural design loads. This work focuses on the development of ... -
Evaluation of Extreme Design Wave Loads for Hull Girder Strength Assessment
Ravinthrakumar, Senthuran (Master thesis, 2016)Ships may operate in severe sea states, which might induce large vertical bending moments. The classification rules have developed empirical curves for the extreme wave-induced vertical bending moments. It is therefore of ... -
Experimental and Theoretical Investigations on the Ship Resistance in Level Ice
Myland, Daniela (Doctoral theses at NTNU;2019:198, Doctoral thesis, 2019)The growing interest in Arctic transportation and field logistics leads to an increasing demand for ships with good ice breaking performance. The ice breaking performance of ships is usually defined by their ability to ... -
Ice Load Impact on the Power Train of Azimuth Propulsion Systems
Krossholm, Andreas Kleven (Master thesis, 2014)This thesis seeks to investigate the advantages of using multibody simulation to develop proper models for power train analyses of azimuth propulsion systems. Azimuth thrusters are commonly installed on ice classed offshore ... -
Ice-propeller impact analysis using an inverse propulsion machinery simulation approach
Polić, Dražen (Doctoral theses at NTNU;2019:235, Doctoral thesis, 2019) -
Integrated multi-domain system modelling and simulation for offshore crane operations
Chu, Yingguang; Æsøy, Vilmar; Ehlers, Sören; Zhang, Houxiang (Journal article; Peer reviewed, 2015)Advanced offshore machinery, such as an offshore crane, usually involves several energy domains. Modelling and simulation of multi-domain systems is challenging because of not only the complexity in modelling of the related ... -
MARSTRUCT benchmark study on nonlinear FE simulation of an experiment of an indenter impact with a ship side-shell structure
Ringsberg, Jonas W; Amdahl, Jørgen; Chen, Bai Qiao; Cho, Sang-Rai; Ehlers, Sören; Hu, Zhiqiang; Kubiczek, Jan M; Korgesaar, Mihkel; Liu, Bin; Marinatos, Janis N; Niklas, Karol; Parunov, Joško; Quinton, Bruce WT; Rudan, Smiljko; Samuelides, Manolis; Soares, Carlos Guedes; Tabri, Kristjan; Villavicencio, Richard; Yamada, Yasuhira; Yu, Zhaolong; Zhang, Shengming (Journal article; Peer reviewed, 2018)This paper presents a benchmark study on collision simulations that was initiated by the MARSTRUCT Virtual Institute. The objective was to compare assumptions, finite element models, modelling techniques and experiences ... -
Model scale investigation of aspects influencing the ice resistance of ships sailing ahead in level ice
Myland, Daniela; Ehlers, Sören (Peer reviewed; Journal article, 2020)For a reliable prediction of the total resistance in ice in an early ship design stage, it is of great importance to have knowledge on the different influencing aspects. Three of the quite poorly investigated aspects of ... -
Numerical Prediction of Ship-Ice Interaction: A Project Presentation
Hahn, Malte; Dankowski, Hendrik; Ehlers, Sören; Erceg, Sandro; Rung, Thomas; Huisman, Michael; Sjöblom, Henrik; Leira, Bernt Johan; Chai, Wei (Chapter; Peer reviewed, 2017)It is inevitable that commercial shipping and oil and gas resource exploitation activities in the Arctic will increase due to decreasing sea ice extent caused by global climate changes. Significantly more demanding and at ... -
Oil spill damage: a collision scenario and financial liability estimations for the Northern Sea Route area
Bambulyak, Alexei; Ehlers, Sören (Peer reviewed; Journal article, 2020)The global demand in energy resources is moving the petroleum industry to the Arctic with its huge resource potential. The lack of infrastructure onshore increases the role of the Arctic marine shipping and the importance ... -
On equivalent ice thickness and machine learning in ship ice transit simulations
Milaković, Aleksandar-Saša (Doctoral theses at NTNU;2019:377, Doctoral thesis, 2019)This thesis presents a contribution to the research field of ship ice transit simulations used for estimating the ship resistance/speed profile in a complex ice field. Namely, two distinct methodological approaches within ... -
Parametric Structural Analysis for a Platform Supply Vessel at Preliminary Design Phase - A Sensitivity Study via Design of Experiments.
Lande Andrade, Sthefano (Master thesis, 2016)Parametric structural design analysis is a promising alternative to diminish the hull's structural mass, resulting in a vessel with higher payload capacity as well as lower construction and maintenance costs. The challenge ...