Blar i NTNU Open på forfatter "Moan, Torgeir"
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Analysis of lifting operation of a monopile for an offshore wind turbine considering vessel shielding effects
Li, Lin; Gao, Zhen; Moan, Torgeir; Ormberg, Harald (Journal article; Peer reviewed, 2014)This study addresses numerical simulations of the lifting operation of a monopile for an offshore wind turbine with a focus on the lowering process. A numerical model of the coupled system of the monopile and vessel is ... -
Analysis of the Reduced Wake Effect for Available Wind Power Calculation during Curtailment - Including Validation Experiments
Bontekoning, Marthijn Peter Cornelis (Master thesis, 2017)With increasing wind power capacity, the impact of wind power on power system operation increases. For a mature integration of large amounts of wind power, controlling wind farm output by temporary curtailment becomes ... -
Assessment of Allowable Sea States During Installation of OWT Monopiles with Shallow Penetration in the Seabed
Li, Lin; Guachamin Acero, Wilson Ivan; Gao, Zhen; Moan, Torgeir (Journal article, 2016)Installation of offshore wind turbines (OWTs) requires careful planning to reduce costs and minimize associated risks. The purpose of this paper is to present a method for assessing the allowable sea states for the initial ... -
Assessment of inhomogeneity in environmental conditions in a Norwegian fjord for design of floating bridges
Cheng, Zhengshun; Svangstu, Erik; Moan, Torgeir; Gao, Zhen (Peer reviewed; Journal article, 2021)Environmental conditions along a very large floating bridge are inhomogeneous due to complex topography and hydrography. Evaluating the inhomogeneity in environment conditions is important for safety design of floating ... -
Assessment of Marine Operations for Offshore Wind Turbine Installation with Emphasis on Response-Based Operational Limits
Acero, Wilson Ivan Guachamin (Doctoral theses at NTNU;2016:336, Doctoral thesis, 2016)This thesis addresses methodologies for assessment of response-based operational limits in terms of allowable vessel responses or sea state parameters, and numerical analyses of current and novel o_shore wind turbine ... -
Assessment of the Dynamic Responses and Allowable Sea States for a Novel Offshore Wind Turbine Tower and Rotor Nacelle Assembly Installation Concept Based on the Inverted Pendulum Principle
Guachamin Acero, Wilson Ivan; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2016)This paper presents a numerical study for preliminary assessment of the dynamic responses and allowable sea states for the installation of an offshore wind turbine (OWT) tower and rotor nacelle assembly (RNA) based on a ... -
Benchmarking of a computational fluid dynamics- based numerical wave tank for studying wave load effects on fixed and floating offshore structures
Nematbakhsh, Ali; Gao, Zhen; Moan, Torgeir (Journal article, 2017)A computational fluid dynamics (CFD) based numerical wave tank (NWT) is developed and verified to study wave load effects on fixed and free floating offshore structures. The model is based on solving Navier–Stokes equations ... -
Bucket Foundation in Clay for OWT Subjected to Combined Cyclic Loads
Chen, Ying (Master thesis, 2014)This thesis project investigates the bucket foundation in clay subjected to cyclic loads. The cyclic irregular loading history in this thesis was represented by the equivalent number of cycles Neq with a certain level of ... -
Buckling of Cylindrical Shells with a Granular Core Under Global Bending: Strength Gains and Imperfection Sensitivity
Cook, Timothy Wade (Master thesis, 2014)Thin cylindrical shells are commonly employed in civil and structural applications in which the dominant loading condition is global bending. In applications such as wind turbine towers and offshore piles, the design of ... -
Comparative analysis of numerically simulated and experimentally measured motions and sectional forces and moments in a floating wind turbine hull structure subjected to combined wind and wave loads
Luan, Chenyu; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2018)Multi-body time-domain finite element models, which implement a recently developed numerical approach for determining forces and moments in floaters, are developed to simulate rigid-body motions and sectional forces and ... -
Comparative experimental study of the survivability of a combined wind and wave energy converter in two testing facilities
Wan, Ling; Gao, Zhen; Moan, Torgeir; Lugni, Claudio (Journal article; Peer reviewed, 2016)Combining the offshore wind and wave energy on an integrated structure or in a farm configuration is beneficial for cost reduction since they could share the infrastructure and the ocean space. The spar torus combination ... -
Comparative Numerical and Experimental Study of two Combined Wind and Wave Energy Concepts
Gao, Zhen; Moan, Torgeir; Wan, Ling; Michailidis, Konstantinos (Journal article, 2016)With a successful and rapid development of offshore wind industry and increased research activities on wave energy conversion in recent years, there is an interest in investigating the technological and economic feasibility ... -
A comparative study of fully coupled and de-coupled methods on dynamic behaviour of floating wind turbine drivetrains
Wang, Shuaishuai; Moan, Torgeir; Nejad, Amir R. (Peer reviewed; Journal article, 2021)Traditionally, drivetrain responses are obtained by a de-coupled analysis, which first involves a global analysis with a simplified representation of the drivetrain, followed by a detailed analysis of the drivetrain with ... -
Comparative Study of Lifting Operations of Offshore Wind Turbine Monopile and Jacket Substructures Considering Vessel Shielding Effects
Li, Lin; Gao, Zhen; Moan, Torgeir (Chapter, 2015)In this paper, the shielding effects from an installation vessel during lifting operations are investigated. The study compared the lifting operations of two commonly used offshore wind turbine substructures: the monopile ... -
Comparative Study On Dynamic Responses of a Semi-submersible Wind Turbine Using a Simplified Aerodynamic Model and a BEM Model
Zhang, Rui (Master thesis, 2013)Due to the high potential of offshore wind energy, a lot of research work is being done around the world on offshore wind turbines. Currently mainly two types of model are used in Marine Technology Department of NTNU to ... -
A comparative study on the dynamic behaviour of 10 MW conventional and compact gearboxes for offshore wind turbines
Wang, Shuaishuai; Rasekhi Nejad, Amir; Bachynski, Erin Elizabeth; Moan, Torgeir (Peer reviewed; Journal article, 2020)This study compares the dynamic behaviour of a conventional and a compact gearbox for the DTU 10 MW wind turbine supported on a monopile offshore structure. The conventional gearbox configuration is composed of two planetary ... -
Comparison of Experimental Data of a Moored Multibody Wave Energy Device With a Hybrid CFD and BIEM Numerical Analysis Framework
Nematbakhsh, Ali; Michailidis, Konstantinos; Gao, Zhen; Moan, Torgeir (Chapter; Peer reviewed, 2015)In the present paper, a hybrid Computational Fluid Dynamics (CFD) and Boundary Integral Element Method (BIEM) framework is developed in order to study the response of a moored Multibody wave Energy Device (MED) to a ... -
Comparison of Numerical Simulation and Model Test for Integrated Installation of GBS Wind Turbine: Sammenligning av numerisk simulering og modellforsøk for installering av GBS vindturbin
Bense, Marvin Phillip (Master thesis, 2014)Reinertsen has developed a new installation concept for the transportation and installation of a fully assembled gravity based foundation offshore wind turbine (GBS-OWT) by means of a support double barge (DB) and standard ... -
Comparison of wave load effects on a TLP wind turbine by using computational fluid dynamics and potential flow theory approaches
Nematbakhsh, Ali; Bachynski, Erin Elizabeth; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2015)Tension Leg Platform (TLP) is one of the concepts which shows promising results during initial studies to carry floating wind turbines. One of the concerns regarding tension leg platform wind turbines (TLPWTs) is the high ... -
Comparison of Wave-induced Response of a TLP Wind Turbine Obtained by CFD Method and Potential Theory
Nematbakhsh, Ali; Bachynski, Erin Elizabeth; Gao, Zhen; Moan, Torgeir (Chapter, 2014)A computational fluid dynamics (CFD) method has been verified and compared with potential theory approach to assess the hydrodynamic loads on a tension leg platform wind turbine (TLPWT). Floating wind turbines have the ...