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Tidal Boundary Layer Flow in Coastal Zones
(Master thesis, 2015)A one-dimensional hydrodynamic model with a two-equation turbulence closure has been used to model shallow-water tidal flow over a complex bottom. The intention was to investigate the applicability of the model on tidal ... -
Tidal boundary layer flow over a flat bottom with vegetation
(Master thesis, 2016)A numerical k-epsilon model has been modified to account for the presence of submerged vegetation. The code has been successfully validated and run against tidal current measurement. The results looks promising. Especially ... -
Tilstandsbasert vedlikehold på tørrgasstetninger
(Master thesis, 2014)Tørrgasstetninger er mekaniske akseltetninger som er plassert på hver sin side av kompressorhuset for å hindre at gass lekker ut til omgivelsene. Tørrgasstetninger benytter gass som tetningsmedium. Gasslekkasje kontrolleres ... -
Time Domain Analysis of Vortex-Induced Vibrations
(Doctoral thesis at NTNU;2016:231, Doctoral thesis, 2016)This thesis deals with the development of a new empirical model of the hydrodynamic loads associated with vortex-induced vibrations (VIV) of slender circular cylinders. The most commonly used VIV analysis tools operate in ... -
Time domain analysis procedures for fatigue assessment of a semi-submersible wind turbine
(Journal article; Peer reviewed, 2015)Long term time domain analysis of the nominal stress for fatigue as- sessment of the tower and platform members of a three-column semi- submersible was performed by fully coupled time domain analyses in Simo- Ri ex-AeroDyn. ... -
Time domain model for calculation of pure in-line vortex-induced vibrations
(Journal article; Peer reviewed, 2017)A time domain model for prediction of cross-flow vortex-induced vibrations (VIV) of slender structures with circular cross section has been under development since 2012. As an extension of this work, a time domain model ... -
Time Domain Modeling and Analysis of Dynamic Gear Contact Force in a Wind Turbine Gearbox with Respect to Fatigue Assessment
(Journal article; Peer reviewed, 2012)The gearbox is one of the most expensive components of the wind turbine system. In order to refine the design and hence increase the long-term reliability, there has been increasing interest in utilizing time domain ... -
Time Domain Modeling of Propeller Forces due to Ventilation in Static and Dynamic Conditions
(Journal article; Peer reviewed, 2020)This paper presents experimental and theoretical studies on the dynamic effect on the propeller loading due to ventilation by using a simulation model that generates a time domain solution for propeller forces in varying ... -
Time Domain Modeling of ROV Umbilical using Beam Equations
(Journal article, 2016)This paper presents a finite element model for representing the cable dynamics of a typical ROV(Remotely Operated Vehicle) umbilical. The goal is to produce a model able to capture the most important dynamic effects of the ... -
Time Domain Simulation of Jack-Up in Second Order Irregular Seas
(Master thesis, 2016)For dynamically sensitive structures or marine structure sujected to large displacements (such as jack-up paltform) the extreme response is often determined on the basis of short term time domain simulation of extreme sea ... -
Time domain simulation of marine riser vortex-induced vibrations in three-dimensional currents
(Peer reviewed; Journal article, 2022)One of the major uncertainties related to present Vortex-Induced Vibrations (VIV) prediction practice is related to the simplification of real multi-directional current profiles into equivalent uni-directional ones. This ... -
Time domain simulation of riser VIV in current and irregular waves
(Journal article; Peer reviewed, 2018)A semi-empirical prediction tool for time domain analysis of cross-flow and in-line vortex-induced vibrations (VIV) is proposed. The model combines concepts from previous publications in a new way, which allows for time ... -
Time domain simulation of vortex-induced vibrations in stationary and oscillating flows
(Journal article, 2016)This paper focuses on the further development of a previously published semi-empirical method for time domain simulation of vortex-induced vibrations (VIV). A new hydrodynamic damping formulation is given, and the necessary ... -
TIME DOMAIN SIMULATION PARAMETERS FOR FATIGUE ASSESSMENT OF AN OFFSHORE GRAVITY BASED WIND TURBINE
(Master thesis, 2018)Renewable sources of energy are becoming more and more important as the years go by due to both technological development and a greener human attitude. Offshore wind turbines are presented as a productive source of energy ... -
Time domain simulations of wind turbine blade installation using a floating installation vessel
(Master thesis, 2017)This paper is aimed to assess the feasibility of the mating of the blade of an OWT by a floating installation vessel. A state of the art analysis of the current practices in the industry shows that jack-up vessels are ... -
Time domain simulations of wind- and wave-induced load effects on a three-span suspension bridge with two floating pylons
(Journal article, 2018)The construction of a three-span suspension bridge with two floating pylons is currently being considered for crossing the 5-km-wide and 550-m-deep Bjørnafjorden in Norway. The bridge design represents a novel concept that ... -
Time domain versus frequency domain VIV modelling with respect to fatigue of a deep water riser
(Master thesis, 2017)In this thesis the new time domain model developed by PhD. Mats J. Thorsen is compared with the current practice, with respect to fatigue of a deep water riser. Current practice is to superposition the fatigue damage due ... -
Time Domain VIV Analysis Tool VIVANA-TD: Validations and Improvements
(Chapter, 2020)An empirical time-domain (TD) vortex-induced vibration (VIV) prediction model has been implemented in a software called VIVANA-TD based on its earlier development by Thorsen at NTNU. It models the synchronization of VIV ... -
Time Domain Vortex-Induced Motion Prediction of Spar-Type Floating Wind Turbine
(Master thesis, 2023)Flytende vind øker for tiden i popularitet og den flytende spar-vindturbinen viser stort potensial til å tre frem som en viktig brikke i den globale energiomstillingen til fornybare kilder. Denne konstruksjonen kan oppleve ... -
Time domain-based gear contact fatigue analysis of a wind turbine drivetrain under dynamic conditions
(Journal article; Peer reviewed, 2013)This paper presents a general approach to predict the contact fatigue life of the gears in the drive-train system of a wind turbine under dynamic conditions. A simplified predictive pitting model that estimates service ...