Blar i Institutt for marin teknikk på dokumenttype "Doctoral thesis"
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A Boundary Element Method Applied to Strongly Nonlinear Wave-Body Interaction Problems
(Doktoravhandlinger ved NTNU, 1503-8181; 2007:141, Doctoral thesis, 2007)A two-dimensional Boundary Element Method (BEM) based on potential flow theory is developed to study wave-body interaction problems with strongly nonlinear effects. In particular, the following problems are studied. One ... -
A higher-order boundary element method and applications to marine hydrodynamics
(Doktoravhandlinger ved NTNU, 1503-8181; 2008:170, Doctoral thesis, 2008) -
A numerical and experimental study of a two-dimensional body with moonpool in waves and current
(Doctoral thesis at NTNU;2015:98, Doctoral thesis, 2015)The present work has relevane for the behaviour of a vessel equipped with a moonpool in ocaean waves. A moonpool is an opening in the middle of the vessel used for various marine operations. Resonant wave oscillations in ... -
A Numerical Study of a Damaged Ship in Beam Sea Waves
(Doktoravhandlinger ved NTNU, 1503-8181; 2009:268, Doctoral thesis, 2009)An important objective of survivability criteria for passenger vessels is to ensure that there is sufficient time called Time To Capsizing (TTC) to evacuate passengers and crew members in case of emergency. This requires ... -
A Numerical Study of Wave-in-Deck Impact using a Two-dimensional Constrained Interpolation Profile Method
(Doktoravhandlinger ved NTNU, 1503-8181; 2009:153, Doctoral thesis, 2009)A Constrained Interpolation Profile method following Hu and Kashiwagi (2004) is developed for wave impact applications. Two-dimensional, unsteady, viscous and incompressible flow is assumed. The numerical model is a finite ... -
A simulation-based design method for arctic maritime transport systems
(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 ... -
A Theoretical and Experimental Study of Wave-induced Hydroelastic Response of a Circular Floating Collar
(Doctoral theses at NTNU;2017:75, Doctoral thesis, 2017)Wave-induced hydroelastic response of a circular plastic collar used as a floater of a net cage in aquaculture is studied by means of theory, model tests and numerical simulations. A low-frequency linear slender-body ... -
A Two-dimensional Numerical and Experimental Study of a Floater with Net and Sinker Tube in Waves and Current
(Doctoral theses at NTNU;2017:111, Doctoral thesis, 2017)In this thesis, nonlinear wave and current forces on a coupled system of a moored floater with net panel and sinker tube is studied. Due to the complexity of the hydrodynamic analysis of a complete three-dimensional fish ... -
Acoustic-Based Probabilistic Localization and Mapping for Unmanned Underwater Vehicles in Aquaculture Operations
(Doctoral theses at NTNU;2020:208, Doctoral thesis, 2020)The aquaculture industry needs automation to meet the world's increasing demand for fish protein. However, it is considered to be one of the most dangerous occupations in Norway due to the required amount of manual labor ... -
Adaptive Sampling for Marine Robotics
(Doctoral theses at NTNU;2019:196, Doctoral thesis, 2019)Maintaining a healthy ocean is of the utmost importance. Having only a limited set of resources available to study this vast domain requires research and science to focus on more efficient data collection. Determining when ... -
Advanced Control Algorithms to Support Automated Offshore Wind Turbine Installation
(Doctoral theses at NTNU;2019:231, Doctoral thesis, 2019)The thesis presents the research on automated offshore wind turbine (OWT)installation. The aim of the project is to find innovative and cost-effective methods for installing and maintaining OWTs. Utilization of wind ... -
Advances in semi-empirical time domain modelling of vortex-induced vibrations
(Doctoral theses at NTNU;2018:135, Doctoral thesis, 2018)Most of today’s prediction tools for vortex-induced vibrations (VIV) operate in the frequency domain, where analysis is restricted to linear systems and steady flows. These modelling limitations provide an unsatisfactory ... -
Aerodynamic Modelling of Floating Wind Turbines
(Doctoral thesis at NTNU;2015:150, Doctoral thesis, 2015)Engineering methods that are commonly used to estimate aerodynamic loads on the rotors of floating wind turbines were originally developed for the analysis of land based, or bottom fixed, wind turbines. In an offshore ... -
Ageing management and life extension of technical systems : concepts and methods applied to oil and gas facilities
(Doktoravhandlinger ved NTNU, 1503-8181; 2013:178, Doctoral thesis, 2013)The oil and gas (O&G) industry is becoming increasingly interested in prolonging the operation of some facilities beyond their original design lifetime. The main challenge when extending the life of an ageing facility is ... -
Aided Inertial Navigation of Underwater Vehicles
(Doctoral theses at NTNU;2018:96, Doctoral thesis, 2018)This thesis is motivated by cost reduction in subsea inspection, maintenance, and repair operations, which requires autonomy and automatic functionality in order to save time and money. Autonomy and automatic functions ... -
An age-based replacement model for repairable systems with attention to high-speed marine diesel engines
(Doktoravhandlinger ved NTNU, 1503-8181; 2008:243, Doctoral thesis, 2008)The background of this thesis is the high number of severe failures of high-speed propulsion engines in high-speed vessels. When number of failures is high, the preventive maintenance comes into particular focus. Hence, ... -
An Experimental Investigation of In-line and Combined In-line and Cross-flow Vortex Induced Vibrations
(Doktoravhandlinger ved NTNU, 1503-8181; 2007:253, Doctoral thesis, 2007)This thesis presents results from an experimental investigation of hydrodynamic forces on a cylinder under prescribed harmonic motions in uniform flow. The purpose of the experiments has been to find hydrodynamic coefficients ... -
An output feedback motion control system for ROVs : guidance, navigation, and control
(Doctoral thesis at NTNU;2015:122, Doctoral thesis, 2015)This doctoral thesis is concerned with two main subjects, namely path generation and motion control of observation class Remotely Operated Vehicles (ROVs). Both of them are examined with an emphasis on the motion control ... -
An ROV toolbox for optical and acoustical seabed investigations
(Doktoravhandlinger ved NTNU, 1503-8181; 2010:74, Doctoral thesis, 2010)This thesis describes a set of optical and acoustical methods for documenting a research site using underwater vehicles. The need for observations in cold-water coral research has formed the design problem in this work. A ... -
Analysis of Ignition and Combustion in Otto Lean-Burn Engines with Prechambers
(Doktoravhandlinger ved NTNU, 1503-8181; 2008:160, Doctoral thesis, 2008)Otto-engines in which the combustion chamber has richer fuel/air mix close to the ignition source and leaner charge further away from the ignition source are often called "stratified charge engines". Stratified charge can ...