Browsing Institutt for marin teknikk by Journals "Ocean Engineering"
Now showing items 1-20 of 137
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A 2D+t approach for the transverse viscous loads in a modular maneuvering model
(Peer reviewed; Journal article, 2021)The importance of the transverse viscous loads, in a modular maneuvering model, is investigated. A method to estimate steady sectional drag coefficients is first presented. A 2D+t approach, which accounts for forward-speed ... -
3D motion dynamics of axisymmetric bodies falling through water
(Journal article; Peer reviewed, 2018)A new simplified method for analysis of 3D motion dynamics of axisymmetric slender bodies falling from air through water is presented. Slender-body theory for potential flow of incompressible water is combined with 2D + t ... -
A comprehensive numerical investigation of the impact behaviour of an offshore wind turbine blade due to impact loads during installation
(Journal article, 2019)For installing offshore wind turbines into deep waters, use of floating crane vessels is essential. One of the major challenges is their sensitivity to wave-induced vessel and crane tip motions, which can cause the impact ... -
A distributed anti-collision decision support formulation in multi-ship encounter situations under COLREGs
(Journal article; Peer reviewed, 2015)A multi-ship anti-collision decision support formulation is studied in a distributed and real time way. Under the general requirements from COLREGs rules and regulations, the performance of course alteration and changing ... -
A numerical study on vortex-induced vibrations and the effect of slurry density variations on fatigue of ocean mining risers
(Journal article; Peer reviewed, 2019)Ocean mining emerges as a way of meeting future demands for valuable minerals. Risers conveying ore from the seabed to the surface must withstand large wave and current loads. In addition, vortex-induced vibrations (VIV) ... -
A probabilistic approach for the quantification of prediction error in deterministic phase-resolved wave forecasting
(Journal article; Peer reviewed, 2018)This paper presents a semi-analytical methodology for the determination of prediction error statistics in deterministic sea wave predictions (DSWP), based on linear wave models. The underlying wave elevation is modelled ... -
A review of structural responses and design of offshore tubular structures subjected to ship impacts
(Journal article, 2018)Over the past decades, the offshore oil and gas industry has developed rapidly. A large number of offshore structures, notably jacket and jack-up platforms, were constructed and installed worldwide. As they are often exposed ... -
Adaptive identification of lowpass filter cutoff frequency for online vessel model tuning
(Peer reviewed; Journal article, 2021)Tuning of vessel models in real-time based on vessel measurements and weather information is of great interest in order to increase the safety and efficiency of marine operations. Vessel motion signals usually contain ... -
An Integrated Dynamic Analysis Method for Simulating Installation of a Single Blade for Wind Turbines
(Journal article; Peer reviewed, 2018)Installation of blades for wind turbines is challenging due to large lifting height and high precision. Assessment of blade dynamic responses during installation needs advanced simulation tools which are limited at present. ... -
Analysis of difference-frequency wave loads and quadratic transfer functions on a restrained semi-submersible floating wind turbine
(Peer reviewed; Journal article, 2021)One of the concerns regarding numerical simulation of floating wind turbines (FWTs) in waves is underprediction of resonant responses in the low-frequency range. In the present work, the difference-frequency wave loads on ... -
Assessing Ship Risk Model Applicability to Marine Autonomous Surface Ships
(Journal article; Peer reviewed, 2018)Marine Autonomous Surface Ships (MASS) are tested in public waters. A requirement for MASS to be operated is that they should be at least as safe as conventional ships. Hence, this paper investigates how far the current ... -
Assessment of allowable sea states for offshore wind turbine blade installation using time-domain numerical models and considering weather forecast uncertainty
(Peer reviewed; Journal article, 2022)Installation of offshore wind turbines, particularly blades, is challenging and should be executed within the allowable limit of sea states to ensure the safety and the efficiency of installation. During the execution phase ... -
Assessment of inhomogeneity in environmental conditions in a Norwegian fjord for design of floating bridges
(Peer reviewed; Journal article, 2021)Environmental conditions along a very large floating bridge are inhomogeneous due to complex topography and hydrography. Evaluating the inhomogeneity in environment conditions is important for safety design of floating ... -
Assessment of methods for short-term analysis of riser collision probability
(Peer reviewed; Journal article, 2021)Reliability- and performance-based design of a riser cluster requires an accurate estimation of the extreme values of the stochastic relative distance between the risers during a given time duration. This study presents a ... -
Assessment of safety barriers for the prevention of cascading events in oil and gas offshore installations operating in harsh environment
(Journal article, 2018)Fire in the topside production area of offshore Oil and Gas (O&G) platforms has the potential to trigger cascading events and may lead to catastrophic consequences for operators, environment and asset. Safety barriers, ... -
A benchmarking exercise for environmental contours
(Peer reviewed; Journal article, 2021)Environmental contours are used to simplify the process of design response analysis. A wide variety of contour methods exist; however, there have been a very limited number of comparisons of these methods to date. This ... -
Changes in surge and pitch decay periods of floating wind turbines for varying wind speed
(Journal article; Peer reviewed, 2019)Recently published experimental results show variations in surge and pitch decay periods of floating wind turbines (FWTs) subjected to different incident wind velocities. This paper explores the external loads acting on a ... -
Comparative experimental study of the survivability of a combined wind and wave energy converter in two testing facilities
(Journal article; Peer reviewed, 2016)Combining the offshore wind and wave energy on an integrated structure or in a farm configuration is beneficial for cost reduction since they could share the infrastructure and the ocean space. The spar torus combination ... -
Comparative investigation: Closed versus semi-closed vertical cylinder-shaped fish cage in waves
(Journal article; Peer reviewed, 2022)A comparative analysis between a closed cage (CC) and a semi-closed/open-bottom cage (OC) in regular, white-noise and irregular waves is presented. Both cages consist of a vertical circular free surface-piercing cylinder ... -
Compensation of bias loads in dynamic positioning of marine surface vessels
(Journal article; Peer reviewed, 2019)This paper investigates different methods for compensating the mean and slowly varying environmental loads, and unmodeled dynamics (bias loads) in dynamic positioning of marine vessels. Four different methods are compared; ...