Blar i NTNU Open på forfatter "Sævik, Svein"
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Numerical Analysis of Combined VIV and Slug Flow in Time Domain
Knudsen, Tor Huse; Sævik, Svein; Thorsen, Mats Jørgen (Chapter; Peer reviewed, 2016)Vortex induced vibrations (VIV) and slug flow are two important aspects for marine risers conveying a multiphase flow, and should be carefully examined due to the influence on the fatigue life of the structure. This article ... -
Numerical investigation of collapse and ductile fracture in X65 offshore pipelines subject to external pressure, bending and axial loads
Hafstad, Jens Mjøen (Master thesis, 2016)An offshore pipeline during S-laying in deep water may be subject to high pressure, bending and tensile loads. In the event of loss of tension the pipe may buckle for sufficiently high external pressures and bending moments. ... -
OMAE2017-62644 The Effect of Stick Stiffness of Friction Models on the Bending Behavior in Non-Bonded Flexible Risers
Dai, Tianjiao; Ye, Naiquan; Sævik, Svein (Chapter; Peer reviewed, 2017)This paper investigates the effect of stick stiffness on the bending behavior in non-bonded flexible risers. The stick stiffness was normally implemented in the friction model for calculating the friction stress between ... -
On prediction of torque in flexible pipe reeling operations using a Lagrangian-Eulerian FE framework
Longva, Vegard; Sævik, Svein (Journal article; Peer reviewed, 2016)In this paper a new framework for FE simulation of reeling operations that utilizes a Lagrangian–Eulerian description of the beam kinematics is proposed. In contrast to the conventional Lagrangian approach, the material ... -
On-Bottom Hydrodynamic Stability of Offshore Pipelines Performing 3D Analysis in SIMLA
Xia, Julia (Master thesis, 2020)Målet med denne masteroppgaven er å utføre en 3D hydrodynamisk stabilitetsanalyse av en undervannsrørledning på sjøbunn, for å demonstrere fordelene med en 3D funksjonalitet sammenlignet med eksisterende metoder. Hydrodynamisk ... -
Onboard Tuning and Uncertainty Estimation of Vessel Seakeeping Model Parameters
Han, Xu (Doctoral theses at NTNU;2021:356, Doctoral thesis, 2021)The accurate prediction of critical vessel motions is essential for safe and cost-efficient marine operations. Compared with the difference-frequency responses that can be compensated by mooring and dynamic positioning ... -
Onboard tuning of vessel seakeeping model parameters and sea state characteristics
Han, Xu; Leira, Bernt Johan; Sævik, Svein; Ren, Zhengru (Peer reviewed; Journal article, 2021)It is essential for a safe and cost-efficient marine operation to improve the knowledge about the real-time onboard vessel conditions. This paper proposes a novel algorithm for simultaneous tuning of important vessel ... -
Optimization of passive heave compensation during Subsea Factory heavy lift operations
Zhou, Weitian (Master thesis, 2017)This thesis is about the study of the effect of heave passive compensation during subsea factory heavy lift operations. All the analysis are based on the data provided by Peter Sandvik, Marintek. The main objective is to ... -
Pipeline Free Span Fatigue Based on DNV RP & Time Domain VIV Modelling Procedures
Vaksdal, Michael Hertz (Master thesis, 2023)Fritt spennende undervannsrør er utsatt for ulike miljøbelastninger, hvorav virvelinduserte vibrasjoner (VIV) er en av de viktigste bidragsyterne til utmattingssvikt. VIV er et selvutløsende fenomen forårsaket av samspillet ... -
Pipeline Walking of High Pressure/Temperature Flowlines
Tveråmo, Camilla (Master thesis, 2013)The offshore pipeline industry are facing more complex design challenges as the oiland gas industry moves into deeper water in search for hydrocarbons. One of thesechallenges are related to high pressure/high temperature ... -
Post Behaviour of Anchors Hooked by Pipelines
Dahle, Lars Johan (Master thesis, 2021)De siste tiårene har utviklingen av undersjøiske installasjoner økt i sammenheng med reduksjon i kostnaden for etablering av dem. I samme tidsrom, og for fremtiden, vil det være en økning av seilaser i Nordsjøen grunnet ... -
Prediction of deepwater riser VIV with an improved time domain model including non-linear structural behavior
Kim, Sangwoo; Sævik, Svein; Wu, Jie; Leira, Bernt Johan (Peer reviewed; Journal article, 2021)In this paper, vortex-induced vibrations (VIV) of deepwater risers including the VIV-induced tension fluctuations were simulated using a time domain VIV model. Data from a large-scale riser experiment was applied for ... -
Reduction of trawl impact loads on pipelines resting exposed on the seabed
Krogstadmo, Truls Wanvik (Master thesis, 2019)I dag finnes havbunnsinstallasjoner rundt omkring i Nordsjøen og Barentshavet med rørledninger som strekker seg totalt over 8800 kilometer på norsk sokkel. Rørledninger eksisterer rundt offshore-anlegget og er koblet til ... -
Response of Flexible Risers in Bend Stiffener Area
Løseth, Kim (Master thesis, 2011)Flexible risers is a vital part of a floating production system (FPS). In order to predict the riser life time, many procedure may be applied. In this thesis it is assumed that the pipe could be represented with help of ... -
Retrieval of Ocean Wave Spectra From X-Band Marine Radar Images Using Inversion Schemes Based on Auto-Spectral Analysis
Radhakrishnan, Gowtham; Leira, Bernt Johan; Gao, Zhen; Sævik, Svein; Christakos, Konstantinos (Chapter, 2023)Estimation of ocean wave conditions is extremely crucial for the planning and execution of demanding marine operations. Further, the Response Based Decision-Making requires accurate wave inputs to derive the responses using ... -
Rigid Pipelay Curve Stability
Andersson, Christian (Master thesis, 2014)Pipeline installation would generally involve curved sections in the horizontal plane, due to existing subsea infrastructure or natural seabed characteristics. At a small curve radius, the lateral seabed friction could be ... -
Riser lift system for deep sea mining
Mao, Haiying (Master thesis, 2018)The growing global demand for rare metals and the declining land mineral resources impel the research on exploring seabed minerals resources. Based on this requirement, some research projects about deep sea mining are ... -
Sammenligning av moment og spiralmodeller for utmatningsanalyse av fleksible stigerør
Liu, Xiaoli (Master thesis, 2014)There are still quite a lot of unknown and unexplainable fields in riser section, whose fatigue damage may cause loss of lives, environmental pollution and threats to the economy. In this thesis, two methods to find the ... -
A Search for Shape
Blokland, Bart Iver van (Doctoral theses at NTNU, 2021:398, Doctoral thesis, 2021)As 3D object collections grow, searching based on shape becomes crucial. 3D capturing has seen a rise in popularity over the past decade and is currently being adopted in consumer mobile hardware such as smartphones and ... -
A Sensitivity Study of Vessel Hydrodynamic Model Parameters
Han, Xu; Sævik, Svein; Leira, Bernt Johan (Chapter, 2020)In the recent decade, maritime and energy industries have realized the potential of using operational data in combination with a virtual replication of the real physical asset, termed the digital twin. The digital twin ...