Blar i NTNU Open på forfatter "Muskulus, Michael"
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A global slamming force model for offshore wind jacket structures
Tu, Ying; Cheng, Zhengshun; Muskulus, Michael (Journal article; Peer reviewed, 2018)Under certain harsh environmental conditions, jacket structures supporting offshore wind turbines might be exposed to plunging breaking waves, causing slamming forces that affect the structural integrity and fatigue life. ... -
A review and comparison of floating offshore wind turbine model experiments
Muskulus, Michael; Stewart, Gordon (Journal article; Peer reviewed, 2016)Floating off shore wind turbines provide more access to deeper water than conventional fixed bottom wind turbines, which expands the viable area for wind energy development, reduces visibility from shore, and can potentially ... -
A review of slamming load application to offshore wind turbines from an integrated perspective
Tu, Ying; Cheng, Zhengshun; Muskulus, Michael (Journal article; Peer reviewed, 2017)In harsh sea conditions, it is possible for offshore wind turbines (OWTs) to be exposed to slamming loads due to breaking waves, especially plunging breaking waves. These slamming loads lead to significant structural ... -
Analytical gradient-based optimization of offshore wind turbine substructures under fatigue and extreme loads
Chew, Kok Hon; Tai, Kang; Ng, E.Y.K.; Muskulus, Michael (Journal article; Peer reviewed, 2016)Design optimization of offshore wind turbine support structures is an expensive task due to the highly-constrained, non-convex and non-linear nature of the design problem. A good depth of detail in the problem formulation ... -
Assessment of monopiles for lifetime extension of offshore wind turbines
Ziegler, Lisa (Doctoral theses at NTNU;2018:209, Doctoral thesis, 2018)Offshore wind is a fast-growing industry contributing to reduce CO2 emissions. Although most offshore wind turbines are still young today, we will face a significant fleet of ageing assets in the near future. The question ... -
Breaking Characteristics and Geometric Properties of Spilling Breakers over Slopes
Alagan Chella, Mayilvahanan; Bihs, Hans; Myrhaug, Dag; Muskulus, Michael (Journal article; Peer reviewed, 2015)A two-phase flow CFD model based on the Reynolds-Averaged Navier–Stokes (RANS) equations coupled with the level set method (LSM) and k − ω turbulence model is used to simulate spilling breakers over a sloping bed. In order ... -
Brief communication: Structural health monitoring for lifetime extension of offshore wind monopiles: can strain measurements at one level tell us everything?
Ziegler, Lisa Sabine; Smolka, Ursula; Cosack, Nicolai; Muskulus, Michael (Journal article; Peer reviewed, 2017)Operators need accurate knowledge on structural reserves to decide about lifetime extension of offshore wind turbines. Load monitoring enables us to directly compare design loads with real loading histories of the support ... -
Characterization of wave slamming forces for a truss structure within the framework of the WaveSlam project
Rausa Heredia, Ignacio Eugenio (Master thesis, 2014)The foundations of offshore wind turbines in shallow water are predominantly truss structures which are exposed to wave slamming forces. In these situations the design of the structure is governed by high and rapid impacts ... -
Comparing a fracture mechanics model to the SN-curve approach for jacket-supported offshore wind turbines: challenges and opportunities for lifetime prediction
Ziegler, Lisa Sabine; Muskulus, Michael (Chapter, 2016)Accurate lifetime predictions are needed for support structures of offshore wind turbines to optimize operation and maintenance and to decide about lifetime extension of aging wind farms. A comparison of a facture mechanics ... -
Comparison of different approaches to load calculation for the OWEC Quattropod jacket support structure
Zwick, Daniel; Schafhirt, Sebastian; Brommundt, Matthias; Muskulus, Michael; Narasimhan, S; Mechineau, Jonathan; Haugsøen, Per (Journal article; Peer reviewed, 2014)Accurate load simulations are necessary in order to design cost-efficient support structures for offshore wind turbines. Due to software limitations and confidentiality issues, support structures are often designed with ... -
Comparison of impulse based substructuring and fully coupled analysis for offshore wind turbines
Verkaik, Niels (Master thesis, 2014)With an ever increasing demand for clean renewable energy, wind energy is a rapidly expanding market. Due to noise and visual pollution as well as limited space on land, offshore wind turbines are getting more popular. One ... -
Comparison of vertically sided model structures with circular and rectangular cross section subjected to ice-induced vibrations in the frequency lock-in regime
Owen, Cody Carlton (Master thesis, 2017)Very recently, offshore wind energy has begun expanding into subarctic regions with seasonally ice-infested waters like the Baltic Sea. For offshore wind turbines with conventional support structures including monopiles ... -
Computer-aided optimization of an offshore jacket for a wind turbine with a simplified load model
Bakkom, Ole Edvard (Master thesis, 2015)In this report the jacket structure of a 5MW reference offshore wind turbine has been explored in terms of structural redundancy and for optimisation of the node locations. This has been done by the creation and utilisation ... -
Coupled Mooring Systems for Floating Wind Farms
Goldschmidt, Marek (Master thesis, 2014)In this work the feasibility of an integrated catenary loose mooring system for offshore floating wind turbines is investigated. The dynamic behavior of different wind farm layouts is analyzed employing the equation of ... -
Coupled mooring systems for floating wind farms
Goldschmidt, Marek; Muskulus, Michael (Journal article; Peer reviewed, 2015)In this paper it is investigated if, by coupling the catenary mooring systems of a number of turbines, the number of lines and anchors needed and subsequently the costs could be reduced and what kind of dynamic phenomena ... -
Decision Support Models for Operations and Maintenance for Offshore Wind Farms: A Review
Seyr, Helene; Muskulus, Michael (Journal article; Peer reviewed, 2019)This paper reviews the state of the art in offshore wind farm operations and maintenance with a focus on decision support models for the scheduling of maintenance. Factors influential to maintenance planning are collected ... -
Decoupled simulations of offshore wind turbines with reduced rotor loads and aerodynamic damping
Schafhirt, Sebastian; Muskulus, Michael (Journal article; Peer reviewed, 2018)Abstract. Decoupled load simulations are a computationally efficient method to perform a dynamic analysis of an offshore wind turbine. Modelling the dynamic interactions between rotor and support structure, especially the ... -
Design optimization with genetic algorithms: How does steel mass increase if offshore wind monopiles are designed for a longer service life?
Ziegler, Lisa Sabine; Rhomberg, Matthieu; Muskulus, Michael (Journal article; Peer reviewed, 2018)Knowledge about the scaling of steel mass of monopiles is needed to decide for which service life an offshore wind farm should be planned. A computer-aided method to optimize monopiles for different fatigue lifetimes was ... -
Design Sensitivity Analysis of the Xrotor Offshore Wind Turbine Jacket Structure
Bjerkebæk, Ane (Master thesis, 2023)X-rotor er et innovativt offshore vindturbin-prosjekt innen fornybar energi. Målet er å utvikle en ny type vindturbin som har en X-formet rotor, en hybrid mellom vertikalt og horisontalt aksedesign. En mulighetsstudie ... -
Detection of plunging breaking waves based on machine learning
Tu, Ying; Cheng, Zhengshun; Muskulus, Michael (Chapter, 2018)Plunging breaking waves that occur in the vicinity of offshore structures can lead to high impulsive slamming loads, which are significant for the structural loading. The occurrence of plunging breaking waves is usually ...