Browsing Institutt for marin teknikk by Title
Now showing items 3138-3157 of 3421
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Thrust loss on azimuthing thrusters due to Coanda effect
(Master thesis, 2010)The main objectives in this master's thesis is to investigate how the Coanda effect influences a thruster jet which further causes a thrust loss. The tendency of a thruster slipstream to be deflected towards a nearby ... -
Thrust Losses on Underwater Snake Robots with Thrusters
(Master thesis, 2017)The main motivation behind this thesis is to study the effects from different thrust losses on an underwater snake robot (USR) with thrusters. In-line velocity fluctuations, transverse velocity fluctuations, thruster-thruster ... -
Thrust Optimisation of an Oscillating Hydrofoil - By Non-Sinusoidal Sway and Yaw Motion
(Master thesis, 2017)Past research has shown that oscillating hydrofoils can enhance the propulsion efficiency significantly compared to traditional propellers. Dynamic stall plays an important role in the thrust generated by an oscillating ... -
Thruster-Assisted Position Mooring of C/S Inocean Cat I Drillship
(Master thesis, 2016)This thesis presents the development of a new research foundation into the Marine Cybernetic Laboratory, the C/S Inocean Cat I Drillship. This is a 1:90 scaled model of an Arctic drillship design by Inocean for Statoil. The ... -
Tidal and Wind Driven Boundary Layer Flow in Coastal Zones
(Master thesis, 2018)The objective with this thesis is to investigate the start-up of a pure wind driven flow, and the effect of an suddenly increasing wind (starting from zero wind speed) on a tidally driven flow. This is done by performing ... -
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 ...