Browsing NTNU Open by Author "Bihs, Hans"
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3D Numerical modelling of pile scour with free surface profile under waves and current using the level set method in model REEF3D
Ahmad, Nadeem; Bihs, Hans; Kamath, Arun; Arntsen, Øivind Asgeir (Chapter, 2016)Wave action stirs up sediments and keeps it in suspension while currents wash it away from the coastal zone. The combined action of the waves and current close to the sediment bed may worsen the situation by creating ... -
A Combined Level Set/Ghost Cell Immersed Boundary Representation for Simulations of Floating Bodies
Bihs, Hans; Kamath, Arun (Journal article; Peer reviewed, 2016)A six degrees of freedom (6DOF) algorithm is implemented in the open-source CFD code REEF3D. The model solves the incompressible Navier–Stokes equations. Complex free surface dynamics are modeled with the level set method ... -
A comparison of wave generation methods simulating extreme waves in a numerical wave tank
Alagan Chella, Mayilvahanan; Bihs, Hans; Arntsen, Øivind Asgeir (Chapter, 2017)Extreme wave conditions emanate from the random and instantaneous interaction of waves during storm events. These wave conditions may cause potentially severe damage to ships and offshore oil and gas structures. There are ... -
A New Level Set Numerical Wave Tank with Improved Density Interpolation for Complex Wave Hydrodynamics
Bihs, Hans; Kamath, Arun; Alagan Chella, Mayilvahanan; Aggarwal, Ankit; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2016)A new three-dimensional numerical wave tank is developed for the calculation of wave propagation and wave hydrodynamics by solving the incompressible Navier–Stokes equations. The free surface is modeled with the level set ... -
A numerical investigation of erosion around offshore pipelines
Ahmad, Nadeem; Bihs, Hans; Kamath, Arun; Arntsen, Øivind Asgeir (Chapter, 2017)In this paper, a numerical investigation is carried out to model sea bed erosion around offshore pipelines deployed at the shoreline. The open-source CFD model REEF3D is used for the numerical modeling. The model solves ... -
Analysis of Different Methods for Wave Generation and Absorption in a CFD-Based Numerical Wave Tank
Miquel, Adria Moreno; Kamath, Arun; Alagan Chella, Mayilvahanan; Archetti, Renata; Bihs, Hans (Journal article; Peer reviewed, 2018)In this paper, the performance of different wave generation and absorption methods in computational fluid dynamics (CFD)-based numerical wave tanks (NWTs) is analyzed. The open-source CFD code REEF3D is used, which solves ... -
Application Of A 6DOF Algorithm For The Investigation Of Impulse Waves Generated Due To Sub-Aerial Landslides
Kamath, Arun; Bihs, Hans; Arntsen, Øivind Asgeir (Chapter, 2017)Inland water bodies such as lakes, rivers and streams are generally considered safe from extreme wave events. Such inland water bodies are susceptible to extreme wave events due to impact of aerial landslides, where a large ... -
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 ... -
Breaking Focused Waves Generated Using the Transient Wave Packet Method and the Breaking Impact Forces on a Vertical Cylinder
Kamath, Arun; Alagan Chella, Mayilvahanan; Bihs, Hans (Chapter, 2019)The presence of vital offshore infrastructure in deeper waters makes it essential to be able to evaluate the properties of steepness-induced breaking waves. An extreme wave event in deep water can be modelled with a transient ... -
Breaking Wave Interaction with a Vertical Cylinder and the Effect of Breaker Location
Kamath, Arun; Alagan Chella, Mayilvahanan; Bihs, Hans; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2016)The open-source CFD model REEF3D is used to simulate plunging breaking wave forces on a vertical cylinder. The numerical results are compared with data from the experiments carried out at the Large Wave Channel, Hannover, ... -
Breaking wave interaction with tandem cylinders under different impact scenarios
Bihs, Hans; Kamath, Arun; Alagan Chella, Mayilvahanan; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2016)The interaction of plunging breaking waves with a pair of cylinders placed in tandem is investigated using an open-source computational fluid dynamics (CFD) model. The model is validated using experimental data for total ... -
CFD Based Study of Steep Irregular Waves for Extreme Wave Spectra
Aggarwal, Ankit; Alagan Chella, Mayilvahanan; Bihs, Hans; Pakozdi, Csaba; Berthelsen, Petter Andreas; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2017)Offshore structures are exposed to irregular sea states. It consists of breaking and non-breaking waves. They experience extreme wave loads perpetually after being installed in the open ocean. Thus, the study of steep waves ... -
CFD Investigations of Wave Interaction with a Pair of Large Tandem Cylinders
Kamath, Arun; Alagan Chella, Mayilvahanan; Bihs, Hans; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2015)Wave forces and the flow field around cylinders placed in a periodic wave field are investigated with a numerical model using the Reynolds-averaged Navier–Stokes equations. The numerical model is validated by simulating ... -
CFD Modeling of Arctic Coastal Erosion due to Breaking Waves
Ahmad, Nadeem; Bihs, Hans; Alagan Chella, Mayilvahanan; Kamath, Arun; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2019)Computational fluid dynamics (CFD) modeling of breaking waves over a slope and the resulting erosion in the case of an Arctic coastline is presented in this study. The study is performed with the open-source numerical model ... -
CFD Modeling of Local Scour Around a Pair of Tandem Cylinders under Wave Conditions
Ahmad, Nadeem; Bihs, Hans; Kamath, Arun; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2015)Local scour in a marine environment can lead to the failure of offshore and coastal structures. This is also the case, when marine infrastructure is built in Arctic conditions. The knowledge and understanding of erosion ... -
CFD Modeling of Varied Flow Conditions Over an Ogee-Weir
Fleit, Gabor; Baranya, Sandor; Bihs, Hans (Journal article, 2017)Accurate estimation of discharge capacity and local hydrodynamics are essential when designing hydraulic structures. Instead of the application of conventionally used empirical relationships, this study introduces a 3D ... -
CFD modelling of irregular and focused waves using wave reconstruction
Aggarwal, Ankit; Alagan Chella, Mayilvahanan; Bihs, Hans; Pakozdi, Csaba; Arntsen, Øivind Asgeir (Chapter, 2017)The real sea state is composed of the focused and steep irregular waves which makes their study very important in the design of offshore wind turbines. Computational Fluid Dynamics (CFD) can be used as an effective tool ... -
CFD Simulations of Multi-Directional Irregular Wave Interaction With a Large Cylinder
Wang, Weizhi; Kamath, Arun; Bihs, Hans (Chapter, 2018)Ocean waves are random by nature and can be regarded as a superposition of a finite number of regular waves travelling in different directions with different frequencies and phases. Cylinder-shaped objects are commonly ... -
CFD Simulations of Roll Motion of a Floating Ice Block in Waves using REEF3D
Bihs, Hans; Kamath, Arun; Alagan Chella, Mayilvahanan; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2015)Floating ice blocks in waves are generally seen in managed ice and in marginal ice zones. Detailed investigations into the hydrodynamics of a floating ice block provides insight into the interaction of floating ice with ... -
CFD Simulations of Wave Propagation and Shoaling over a Submerged Bar
Kamath, Arun; Bihs, Hans; Alagan Chella, Mayilvahanan; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2015)The wave propagation over a submerged bar is simulated using the open source CFD model REEF3D and the numerical results are compared to the experimental data. The transformation of the wave resulting in higher harmonics ...