Browsing NTNU Open by Author "Sævik, Svein"

Now showing items 101-120 of 139

    • Simulating fundamental and higher harmonic VIV of slender structures 

      Ulveseter, Jan Vidar; Thorsen, Mats Jørgen; Sævik, Svein; Larsen, Carl Martin (Journal article; Peer reviewed, 2019)
      Vortex-induced vibrations (VIV) of slender marine structures are complicated response processes, where a number of distinct frequency components might be simultaneously active. These are categorized as fundamental and ...

    • Simulating High-Mode Vortex-Induced Vibration of a Riser in Linearly Sheared Current Using an Empirical Time-Domain Model 

      Kim, Sangwoo; Sævik, Svein; Wu, Jie; Leira, Bernt Johan (Peer reviewed; Journal article, 2021)
      As the development of offshore oil and gas continues to move into deeper waters, the risers connecting the seabed infrastructure to the offshore platform are getting longer. This means that vortex-induced vibration (VIV) ...

    • Simulating riser VIV in current and waves using an empirical time domain model 

      Thorsen, Mats Jørgen; Sævik, Svein (Chapter; Peer reviewed, 2017)
      The theoretical background of an empirical model for time domain simulation of VIV is reviewed. This model allows the surrounding flow to be time varying, which is in contrast to the traditional frequency domain tools. The ...

    • Simulation of Anchor Loads on Pipelines 

      Jónsdóttir, Kristbjörg Edda (Master thesis, 2016)
      Incidents where anchor and pipeline interact are rare, but such an event can have drastic consequences. In the report, "Pipeline and Riser Loss of Containment" by HSE, published in 2001 for the UK sector, 44 incidents ...

    • Simulation of Anchor Loads on Pipelines 

      Pettersen, Torunn Omnes (Master thesis, 2017)
      Anchor loads on pipelines are in general a rarely occurring event, but the severity when it happens could easily jeopardize the integrity of any pipeline. The environmental and economic consequences of an accident caused ...

    • Snaking Behavior of Umbilicals 

      Moheudden, Sharif Mohammad (Master thesis, 2014)
      Umbilical is a hardware element that connects the subsea systems to the top side systems of a floating production unit. During its manufacture, storage and installation, sometimes it shows behaviour like snake as found in ...

    • Sprekkvekst av rørsveiser under S-installasjon 

      Suul, Martin Aunemo (Master thesis, 2013)
      Sub-sea pipelines represent the most cost effective way of transporting oil & gas from the sub-sea field to the market. S-lay is the dominant installation method due to the horizontal firing line enabling several welding ...

    • State-of-the-Art Review of Vortex-Induced Motions of Floating Offshore Wind Turbine Structures 

      Yin, Decao; Passano, Elisabeth; Jiang, Fengjian; Lie, Halvor; Wu, Jie; Ye, Naiquan; Sævik, Svein; Leira, Bernt Johan (Peer reviewed; Journal article, 2022)
      The motivation for this study is the fast development of floating offshore wind energy and the immature methodology and engineering practice related to predictions of vortex-induced motions (VIM). Benefiting from the oil ...

    • Static analysis of interaction between two adjacent top tensioned risers with consideration of wake effects 

      Leira, Bernt Johan; Sævik, Svein; Fu, Ping; Tian, Deqiang; Fan, Honghai (Peer reviewed; Journal article, 2019)
      Collision between adjacent risers has become an important issue as the oil and gas industry moves to deeper waters. In order to estimate the clearance between two marine risers, a static analysis which is mainly concerned ...

    • Stochastic modelling of cross-flow vortex-induced vibrations 

      Ulveseter, Jan Vidar; Thorsen, Mats Jørgen; Sævik, Svein; Larsen, Carl Martin (Journal article, 2017)
      Semi-empirical models are commonly used to predict vortex-induced vibrations (VIV). Empirical parameters are often based on forced harmonic motion tests of short rigid cylinders in one degree of freedom, which is a significant ...

    • Strength Analysis Modelling of Flexible Umbilical Members for Marine Structures 

      Sævik, Svein; Gjøsteen, Janne Kristin Økland (Journal article; Peer reviewed, 2012)
      This paper presents a 3-dimensional finite element formulation for predicting the behaviour of complex umbilical cross-sections exposed to loading from tension, torque, internal and external pressure including bending. ...

    • Study on the static behavior of installing a deep-water drilling riser on a production platform 

      Tian, Deqiang; Fan, Honghai; Leira, Bernt Johan; Sævik, Svein (Peer reviewed; Journal article, 2020)
      Riser interference caused by wake effects between adjacent risers severely threatens the safety during riser installation process on a Dry-Tree Tension Leg Platform (TLP) system. Due to the ignorance of interference effect, ...

    • System Uncertainty Effects on the Wave Frequency Response Of Floating Vessels Based on Polynomial Chaos Expansion 

      Radhakrishnan, Gowtham; Han, Xu; Sævik, Svein; Gao, Zhen; Leira, Bernt Johan (Chapter, 2021)
      From a mathematical viewpoint, the frequency domain analysis of vessel motion responses due to wave actions incorporates the integration of system dynamics idealized in terms of response amplitude operators (RAOs) for 6 ...

    • System Uncertainty Effects on the Wave Frequency Response of Floating Vessels Based on Polynomial Chaos Expansion 

      Radhakrishnan, Gowtham; Han, Xu; Sævik, Svein; Gao, Zhen; Leira, Bernt Johan (Peer reviewed; Journal article, 2021)
      From a mathematical viewpoint, the frequency domain analysis of vessel motion responses due to wave actions incorporates the integration of system dynamics idealized in terms of response amplitude operators (RAOs) for 6 ...

    • Systematic Evaluation of VIV Prediction for Riser with Partial Strake Coverage 

      Drengsrud, Håkon (Master thesis, 2019)
      Med utgangspunkt i doktorgradsavhandlingene til Mats J. Thorsen og Jan V. Ulveseter presenterer denne oppgaven en semi-empirisk tidsplan-modell som er i stand til å predikere virvelinduserte vibrasjoner (VIV) for stigerør ...

    • Tensegrity-Based Semi-Submersible Support Structure for a Floating Offshore Wind Turbine 

      Corona, Maiten Kase (Master thesis, 2022)
      I dyptliggende havområder er muligens flytende vindturbiner den mest kostnadseffektive løsningen for å utnytte potensialet til offshore vindenergi. Behovet for mer bærekraftige energikilder øker, og offshore vind viser ...

    • Tensile armour buckling in flexible pipes 

      Nygård, David (Master thesis, 2012)
      The exible pipelines has been widely used by the oil and gas industry the lastdecades and this trend is expected to continue as the operating depths are increasedfurther. For deep water applications the radial and lateral ...

    • Time Domain Analysis of Vortex-Induced Vibrations 

      Thorsen, Mats Jørgen (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 model for calculation of pure in-line vortex-induced vibrations 

      Ulveseter, Jan Vidar; Sævik, Svein; Larsen, Carl Martin (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 simulation of marine riser vortex-induced vibrations in three-dimensional currents 

      Kim, Sangwoo; Sævik, Svein; Wu, Jie; Leira, Bernt Johan (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 ...