Blar i Institutt for marin teknikk på dokumenttype "Chapter"
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2D Numerical Study on Wake Scenarios for a Flapping Foil
(Chapter, 2021)Fishes are talented swimmers. Depending on the propulsion mechanisms many fishes can use flapping tails and/or fins to generate thrust, which seems to be connected to the formation of a reverse von Kármán wake. In the ... -
A 2D Experimental and Numerical Study of Moonpools With Recess
(Chapter, 2018)Moonpool resonance is investigated in a two-dimensional setting in terms of regular, forced heave motions of a model with moonpool with different rectangular-shaped recess configurations. A recess is a reduced draft zone ... -
A comparative fatigue reliability study for key structural components of offshore wind turbines
(Chapter, 2018)In this paper, the fatigue reliability of blade root and tower base of a jacket wind turbine, the OC4 semi-submersible wind turbine and a land-based wind turbine is investigated and compared. The fatigue reliability of ... -
A Comparison Study on the Hydroelasticity of Two Types of Floating Bridges in Inhomogeneous Wave Conditions
(Chapter, 2018)Due to the interaction between elastic structural deformations and fluid motions, the responses of floating bridges should be analyzed by hydroelasticity methods. We firstly employed a linear time-domain approach, based ... -
A design methodology for resilience in fleets for service operations
(Chapter, 2016)In this paper, we present a new conceptual design methodology for increasing the resilience in complex operations involving a fleet of ships. The objective of the methodology is to support design decisions to reduce ... -
A discussion of risk influencing factors for maritime accidents based on investigation reports
(Chapter, 2017)This paper reports findings from a review of investigation reports from maritime accidents. Based on a systematic analysis of 95 reports, we discuss a selection of typical causes and circumstances for serious maritime ... -
A Global-local Damage Assessment Methodology for Impact Damage on Offshore Wind Turbine Blades during Lifting Operations
(Chapter, 2018)Lifting the latest generation offshore wind turbines using floating crane vessels is extremely challenging. This comes with an elevated risk of blades impacting the tower or surrounding structures due to excessive crane ... -
A harmonic polynomial method based on Cartesian grids with local refinement for complex wave-body interactions
(Chapter, 2018)A novel numerical method is proposed for complex potential free-surface flows of incompressible liquids with and without bodies. The present method combines high-order harmonic polynomials with Cartesian grids with local ... -
A multi-body dynamic model based on bond graph for maritime hydraulic crane operations
(Chapter; Peer reviewed, 2015)This paper presents a bond graph model of a maritime crane lifting system comprised of a 3DOFs crane with three revolute joints, a winch, a segment of wire, and a pendulum load. The multi-body model contains the dynamic ... -
A Numerical Study on a Flopper Stopper for Leg Positioning of a Jack-Up Barge
(Chapter; Peer reviewed, 2017)Jack-up barges are commonly used for marine operations in the offshore oil and gas, and offshore wind industries. A critical phase within the marine operation activities is the positioning of the jack-up legs onto the ... -
A Numerical Study on Stratified Shear Layers With Relevance to Oil-Boom Failure
(Chapter, 2014)Interface dynamics of two-phase flow, with relevance for leakage of oil retained by mechanical oil barriers, is studied by means of a 2D lattice-Boltzmann method combined with a phase-field model for interface capturing. ... -
A particle filter SLAM approach to online iceberg drift estimation from an AUV
(Chapter; Peer reviewed, 2017)Using autonomous underwater vehicles (AUVs) for mapping the underwater topography of sea-ice and icebergs, or detecting keels of ice ridges, is foreseen as an enabling technology in future Arctic offshore operations. This ... -
A Semi-Analytical Method for Calculating the Hydrodynamic Force on Perforated Plates in Oscillating Flow
(Chapter, 2019)A two-dimensional numerical analysis on the hydrodynamic force of perforated plates in oscillating flow is presented, and a new semi-analytical force model is proposed. Plates with ten different perforation ratios, τ, from ... -
A Structure Preserving Power System Frequency Model for Dynamic Positioning Vessels
(Chapter; Peer reviewed, 2017)This paper adapts a structure preserving model to on-board power plants. The model, originally developed for land-based power systems, is expanded for the larger frequency range allowable to on-board plants. State-space ... -
A Summary of the Recent Work at NTNU on Marine Operations Related to Installation of Offshore Wind Turbines
(Chapter, 2018)In this paper, a summary of the recent work at NTNU on the installation of offshore wind turbines using jack-up and floating vessels will be reported. The wind turbine components considered here are the monopile foundations ... -
A system for automated vision-based sea-ice concentration detection and floe-size distribution indication from an icebreaker
(Chapter; Peer reviewed, 2017)This paper presents a ship-mounted multi-lens camera system for sea-ice monitoring and algorithms to automatically evaluate the sea-ice concentration and to indicate the floe-sizes in a radius of 100 meter around the vessel. ... -
A Systematic Design Approach of Gripper’s Hydraulic System Utilized in Offshore Wind Turbine Monopile Installation
(Chapter, 2018)This paper presents a systematic approach for designing the hydraulic mechanism as a part of the gripper system employed in offshore wind turbine monopile installation. Traditionally, such equipments used in marine operation ... -
A Time-Domain Method for Hydroelastic Analysis of Floating Bridges in Inhomogeneous Waves
(Chapter; Peer reviewed, 2017)Based on the three dimensional potential theory and finite element method (FEM), this paper presented a method for time-domain hydroelastic analysis of a floating bridge in inhomogeneous waves. A floating bridge in both ... -
Abnormal wave slamming impact of stiffened cylinders
(Chapter, 2023)The structural response of a stiffened cylinder due to slamming impact is studied using the ALE method in LS-Dyna. The numerical modelling approach is in the first place verified against experimental results from unstiffened ... -
Accounting for human failure in autonomous ship operations
(Chapter, 2018)