Browsing Institutt for marin teknikk by Issue Date
Now showing items 501-520 of 3432
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Design and Analysis of Steel Catenary Riser Systems for Deep Waters
(Master thesis, 2014)The global growing demand of energy leads the oil and gas industry into deeper waters and harsher environments as current fields are being depleted. This results in need for more advanced technologies to ensure that the ... -
Sea floor geometry approximation and altitude Control of ROVs
(Journal article; Peer reviewed, 2014)This paper presents a method for sea floor geometry approximation in a local region beneath a remotely operated vehicle (ROV) for use in altitude control. The method is based on Doppler velocity log (DVL) altitude measurements ... -
Large Eddy Simulations of flow around a smooth circular cylinder in a uniform current in the subcritical flow regime
(Journal article; Peer reviewed, 2014)Three-dimensional flow around a circular cylinder in a steady, uniform current at subcritical Reynolds numbers (Re) is investigated. The flow is simulated using Large Eddy Simulations (LES) with Smagorinsky subgrid scale ... -
Roll-yaw coupling effects on parametric resonance for a ship in regular waves
(Chapter, 2014)This work represents a further step of the physical study documented by Greco and Lugni (2012b) and Greco et al. (2014). Three-dimensional experiments have been performed on a FPSO model in regular waves to investigate the ... -
ROV Control System for Positioning of Subsea Modules
(Master thesis, 2014)Installation of deep water Xmas trees for subsea oil production is sometimes done by lowering the tree using one wire. Xmas trees are interfacing with other equip- ment on the seafloor and will therefore need to be positioned, ... -
A numerical study of the second-order wave excitation of ship springing by a higher-order boundary element method
(Journal article; Peer reviewed, 2014)This paper presents some of the efforts by the authors towards numerical prediction of springing of ships. A time-domain Higher Order Boundary Element Method (HOBEM) based on cubic shape function is first presented to solve ... -
Wave-Induced Accelerations of a Fish-Farm Elastic Floater: Experimental and Numerical Studies
(Chapter; Peer reviewed, 2014)Numerical simulations and experiments of an elastic circular collar of a floating fish farm are reported. The floater model without netting structure is moored with nearly horizontal moorings and tested in regular deep-water ... -
Modelling and Control of Thruster Assisted Position Mooring System for a Semi-submersible: Analysis and Model Testing
(Master thesis, 2014)For harsh weather, nonlinear effects dominate the dynamics to a larger extent than for calm weather. The low frequency dynamics of a moored vessel are excited by second order wave drift forces. To counteract the low-frequency ... -
Critical Assessment of Non-linear Wave Loads in the Design of Offshore Wind Turbines
(Master thesis, 2014)Good wind conditions make Dogger Bank a well suited site for offshore wind industry. The harsh environment combined with shallow water, create significant non-linear wave loads which must be accounted for in the ultimate ... -
Analysis of Loss of Position Incidents for Dynamically Operated Vessels
(Master thesis, 2014)This project sought to identify the causal factors related to loss of position incidents for dynamically positioned vessels, and to explore the possibility of using a Bayesian Belief Network (BBN) to model the identified ... -
Verification and Examination Management of Complex Systems
(Journal article; Peer reviewed, 2014)As ship systems become more complex, with an increasing number of safety-critical functions, many interconnected subsystems, tight integration to other systems, and a large amount of potential failure modes, several industry ... -
1453. Comparison of the ride performance of an integrated suspension model
(Journal article; Peer reviewed, 2014)Vehicle suspension is one of the important components to reduce vibration from the road. The vehicle seat suspension acts as another component to provide ride comfort, especially to reduce driver fatigues for long hour’s ... -
A prognostic method for fault detection in wind turbine drivetrains
(Journal article; Peer reviewed, 2014)In this paper, a prognostic method is presented for fault detection in gears and bearings in wind turbine drivetrains. This method is based on angular velocity measurements from the gearbox input shaft and the output to ... -
Full-Scale Sea Trials of a Motion Control System for ROVs Based on a High-Gain State Observer
(Journal article, 2014)This paper reports selected results from full-scale sea trials, along with the description of the digital version implemented in practice, of a Motion Control System (MCS) previously proposed by the authors in the ... -
Design and Dynamic Analysis of Tension Leg Platform Wind Turbines
(Doktoravhandlinger ved NTNU, 1503-8181; 2014:86, Doctoral thesis, 2014)There is an increasing interest in using wind turbines oshore, and in deeper water. The tension leg platform wind turbine (TLPWT) concept is promising for intermediate (45 - 150 m) or deep (> 150 m) water. The limited ... -
Experimental Investigation of Marine Fouling on Piles in Currents
(Master thesis, 2014)Various effects of marine fouling on piles have been addressed through a literature study and an experimental investigation. The experimental investigation was conducted on circular cylinders in steady current at subcritical ... -
Factors Influencing Machinery System Selection for Complex Operational Profiles
(Master thesis, 2014)BackgroundThe environmental consequences, caused by global emission of green house gases (GHG), have received increasingly concern in recent years. CO2 emissions from the maritime sector represent 3,3% of the world s total ... -
Image Techniques for Identifying Sea-Ice Parameters
(Journal article; Peer reviewed, 2014)The estimation of ice forces are critical to Dynamic Positioning (DP) operations in Arctic waters. Ice conditions are important for the analysis of ice-structure interaction in an ice field. To monitor sea-ice conditions, ... -
A simulation-based decision support tool for arctic field logistics
(Master thesis, 2014)As the global demand for energy continues to rise, the oil and gas industry investigates new opportunities for oil and gas production in more remote areas. Promising estimation of oil and gas reserves in the Arctic areas ... -
Dynamic Thrust Allocation
(Master thesis, 2014)The purpose of this Thesis is to research the literature of thrust allocation, thruster modelling and maneuvering design, as well as to design and simulate various dynamic thrust allocation algorithms. Vessels with dynamic ...