Øivind Arntsen | Norwegian University of Science and Technology (original) (raw)
Papers by Øivind Arntsen
The interaction of breaking waves with marine structures involves complex free surface deformatio... more The interaction of breaking waves with marine structures involves complex free surface deformation and instantaneous loading on the structural members. A typical offshore platform or a coastal structure consists of several vertical and horizontal members exposed to breaking wave action. The breaking wave hydrodynamics and the effect of neighbouring cylinders on multiple cylinders placed in near vicinity is important due to force amplification or reduction resulting from interaction between the cylinders. The kinematics of breaking waves and the hydrodynamics of breaking wave interaction with a single vertical cylinder have been studied in detail in current literature. Studies have established that the location of a cylinder with respect to the wave breaking point has a major influence on the breaking wave forces on the cylinder. These studies have to be extended to investigate the hydrodynamics of cylinders placed close to each other to understand the modifications in the force regi...
Scour and Erosion
Wave action stirs up sediments and keeps it in suspension while currents wash it away from the co... more 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 excessive sediment transport leading to the failure of hydraulic structures. In this study, numerical modeling of local scour under waves and current is carried out using the open source CFD model REEF3D, which solves the Navier-Stokes equation using the finite difference method. The simulated flow field from the Navier-Stokes equations is coupled with sediment transport algorithms in a numerical waves tank. Further, the calculated bedload and suspended load are linked with the Exner formula to calculate bed elevation changes. The free surface and scoured bed surface are captured using the level set method. Two case scenarios, namely scour under waves and scour under current are run until the equilibrium scour condition is achieved. The simulated results are compared with experimental data of Link (2006) and Sumer & Fredsoe (2001). Good comparison between experimental data and simulated results is observed. It is observed that for equal flow velocity in the flume, sediment transport under current only condition is larger than under waves alone.
Energy Procedia
Offshore wind turbine substructures consisting of cylindrical members are exposed to highly non-l... more Offshore wind turbine substructures consisting of cylindrical members are exposed to highly non-linear and breaking waves in shallow waters [1]. Those structures experience extreme impulsive loads of short duration from breaking waves that can cause permanent structural damage[2]. The main purpose of the present paper is to investigate the wave impact forces on a slender cylinder from plunging breaking waves in shallow waters both experimentally and numerically. The present study consists of two major parts: laboratory measurements and numerical simulations. The laboratory experiments are performed with regular waves. Plunging breaking waves are generated and free surface elevations are measured around the cylinder. Next, numerical simulations are carried out in the three-dimensional numerical wave tank REEF3D. The model is based on the incompressible Reynolds-averaged Navier-Stokes equations together with the k − ω for turbulence and the level set method for free surface. The numerical results are compared with the laboratory measurements in order to validate the numerical model. A good agreement between the computed results and the experimental data is seen for the breaking wave properties. Further, the breaking wave forces and the free surface deformations during the interaction of plunging breaking waves with a vertical cylinder are investigated and they are reasonably well represented in the numerical simulations.
International Journal of Offshore and Polar Engineering
Offshore structures are exposed to irregular sea states. It consists of breaking and non-breaking... more 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 is an important factor in the design of offshore structures. In the present study, a numerical investigation is performed to study steep irregular waves in deep water. The irregular waves are generated using the Torsethaugen spectrum which is a double-peaked spectrum defined for a locally fully developed sea. The Torsethaugen spectrum takes both the sea and swell waves into account. Thus, the generated waves can be very steep. The numerical investigation of such steep waves is quite challenging due to their high wave steepness and wave-wave interaction. The present investigation is performed using the open-source computational fluid dynamics (CFD) model. The wave generation and propagation of steep irregular waves in the numerical model is validated by comparing the numerical wave spectrum with the experimental input wave spectrum. The numerical results are in a good agreement with experimental results. The changes in the spectral wave density during the wave propagation are studied. Further, the double-hinged flap wavemaker is also tested and validated by comparing the numerical and experimental free surface elevation over time. The time and the frequency domain analysis is also performed to investigate the changes in the free surface horizontal velocity. Complex flow features during the wave propagation are well captured by the CFD model.
Journal of Offshore Mechanics and Arctic Engineering
The main purpose of the study is to investigate the breaking wave interaction with a group of fou... more The main purpose of the study is to investigate the breaking wave interaction with a group of four circular cylinders. The physical process of wave breaking involves many parameters, and an accurate numerical modeling of breaking waves and the interaction with a structure remain a challenge. In the present study, the open-source computational fluid dynamics (CFD) model REEF3D is used to simulate the breaking wave interaction with multiple cylinders. The numerical model is based on the incompressible Reynolds-averaged Navier–Stokes (RANS) equations, the level set method for the free surface, and the k–ω model for turbulence. The numerical model is validated with experimental data of large-scale experiments for the free surface elevation and the breaking wave force on a single cylinder. A good agreement is obtained between the numerical results and experimental data. Two different configurations with four cylinders are examined: in-line square configuration and diamond square configur...
International Journal of Offshore and Polar Engineering
Journal of Offshore Mechanics and Arctic Engineering
Wave loads from breaking waves on offshore wind turbine (OWT) substructures in shallow waters sti... more Wave loads from breaking waves on offshore wind turbine (OWT) substructures in shallow waters still remain uncertain. The interaction of breaking waves with structures is characterized by complex free surface deformations, instantaneous impact of the water mass against the structure, and consequently large wave forces on the structures. The main objective of the paper is to investigate wave impact pressures and kinematics during the interaction of breaking waves with a vertical cylinder using the open-source computational fluid dynamics (CFD) model REEF3D. The model is based on the Reynolds-averaged Navier–Stokes (RANS) equations coupled with the level set method and k–ω turbulence model. Three wave impact conditions are considered in this study. The numerically simulated free surface deformations around the cylinder during the breaking wave interaction are also presented for different wave impact conditions. For three wave impact conditions, the wave impact pressure and the horizon...
Volume 2: Prof. Carl Martin Larsen and Dr. Owen Oakley Honoring Symposia on CFD and VIV
Currents and waves cause flow-structure interaction problems in systems installed in the ocean. P... more Currents and waves cause flow-structure interaction problems in systems installed in the ocean. Particularly for bluff bodies, vortices form in the body wake, which can cause strong structural vibrations (Vortex-Induced Vibrations, VIV). The magnitude and frequency content of VIV is determined by the shape, material properties, and size of the bluff body, and the nature and velocity of the oncoming flow. Riser systems are extensively used in the ocean to drill for oil wells, or produce oil and gas from the bottom of the ocean. Risers often consist of a central pipe, surrounded by several smaller cylinders, including the kill and choke lines. We present a series of experiments involving forced in-line and cross flow motions of short rigid sections of a riser containing 6 symmetrically arranged kill and choke lines. The experiments were carried out at the MIT Towing Tank. We present a systematic database of the hydrodynamic coefficients, consisting of the forces in phase with velocity...
Journal of Offshore Mechanics and Arctic Engineering
On several occasions, freak waves have been observed in the past, some causing severe damage. In ... more On several occasions, freak waves have been observed in the past, some causing severe damage. In order to model such extreme wave conditions, one possibility is to use focused waves of first- or second-order based on irregular sea-state wave spectra. The wave phase is chosen such that the waves focus at a predetermined location and time, but the individual wave components become steep and start breaking before the focus location for large amplitudes. In this study, transient wave packets are used for extreme wave generation. Extreme waves are generated that are higher and only break at the concentration point using the transient wave packets method implemented in the open-source CFD model REEF3D. Model validation is performed by comparison to experimental results. The generation of wave packets with an 8.3 times shorter focus distance is investigated and the wave is replicated in a shorter domain with a 9% higher crest. The method is further used to generate a steepness induced-brea...
Journal of Offshore Mechanics and Arctic Engineering
Harbors are important infrastructures for an offshore production chain. These harbors are protect... more Harbors are important infrastructures for an offshore production chain. These harbors are protected from the actions of sea by breakwaters to ensure safe loading, unloading of vessels and also to protect the infrastructure. In current literature, research regarding the design of these structures is majorly based on physical model tests. In this study a new tool, a three-dimensional (3D) numerical model is introduced. The open-source computational fluid dynamics (CFD) model REEF3D is used to study the design of berm breakwaters. The model uses the Volume-averaged Reynolds-averaged Navier-Stokes (VRANS) equations to solve the porous flows. At first, the VRANS approach in REEF3D is validated for flow through porous media. A dam break case is simulated and comparisons are made for the free surface both inside and outside the porous medium. The numerical model REEF3D is applied to show how to extend the database obtained with purely numerical results, simulating different structural alte...
Journal of Waterway, Port, Coastal, and Ocean Engineering
The interaction of plunging breaking waves with a pair of cylinders placed in tandem is investiga... more The interaction of plunging breaking waves with a pair of cylinders placed in tandem is investigated using the open-source computational fluid dynamics (CFD) model REEF3D. The model is validated using experimental data for total wave forces and free surface elevations for breaking wave interaction with a single cylinder. Wave interaction with tandem cylinders is investigated for four different wave impact scenarios on the first cylinder and six different distances between the cylinders in each scenario. Wave forces on the upstream cylinder are generally found to be less than the forces on a single cylinder for a particular scenario. The force on the downstream cylinder is lower than the force on the upstream cylinder when the breaker tongue impacts the first cylinder. Under conditions where the breaker tongue impacts the downstream cylinder around the wave crest level, the wave force on the downstream cylinder is higher than the force on the upstream cylinder. The wave forces experienced by the tandem cylinders is highly influenced by the location of the breaking point with respect to the cylinders and the distance between the cylinders.
Engineering Applications of Computational Fluid Mechanics
Wave propagation over a submerged bar is simulated using the open source CFD model REEF3D with va... more Wave propagation over a submerged bar is simulated using the open source CFD model REEF3D with various incident wave heights to study shoaling, wave breaking features and the process of wave decomposition into higher harmonics for relatively long waves of kd = 0.52. The computed free surface elevations are compared with experimental data and good agreement is obtained for both non-breaking and spilling breaking waves for both the wave phase and free surface elevation, which has been difficult to obtain in current literature. The differences in the mode of wave shoaling over the weather side slope and the wave decomposition over the lee side slope of the submerged bar are discussed. The evolution of spilling breakers and plunging breakers over the bar crest is also studied. It is found that the free surface elevation continuously increases due to shoaling in the case of non-breaking waves, whereas breaking waves propagate with much lower free surface elevations after breaking over the bar crest. The power spectra of the free surface elevations at various locations indicate that the wave energy in the fundamental frequency is reduced by 76% for the non-breaking wave with kA = 0.015 and by about 90% in other cases with higher incident wave heights with kA = 0.023−0.034 due to energy dissipation and energy transfer to higher harmonic components as the wave propagates over the submerged bar.
Journal of Waterway, Port, Coastal, and Ocean Engineering
Journal of Offshore Mechanics and Arctic Engineering
Many offshore constructions and operations involve water impact problems such as water slamming o... more Many offshore constructions and operations involve water impact problems such as water slamming onto a structure or free fall of objects with subsequent water entry and emergence. Wave slamming on semisubmersibles, vertical members of jacket structures, crane operation of a diving bell, and dropping of free fall lifeboats are some notable examples. The slamming and water entry problems lead to large instantaneous impact pressures on the structure, accompanied with complex free surface deformations. These need to be studied in detail in order to obtain a better understanding of the fluid physics involved and develop safe and economical design. Numerical modeling of a free falling body into water involves several complex hydrodynamic features after its free fall such as water entry, submergence into water and resurfacing. The water entry and submergence lead to formation of water jets and air cavities in the water resulting in large impact forces on the object. In order to evaluate th...
Journal of Offshore Mechanics and Arctic Engineering
For the stability of offshore structures, such as offshore wind foundations, extreme wave conditi... more For the stability of offshore structures, such as offshore wind foundations, extreme wave conditions need to be taken into account. Waves from extreme events are critical from the design perspective. In a numerical wave tank, extreme waves can be modeled using focused waves. Here, linear waves are generated from a wave spectrum. The wave crests of the generated waves coincide at a preselected location and time. Focused wave generation is implemented in the numerical wave tank module of REEF3D, which has been extensively and successfully tested for various wave hydrodynamics and wave–structure interaction problems in particular and for free surface flows in general. The open-source computational fluid dynamics (CFD) code REEF3D solves the three-dimensional Navier–Stokes equations on a staggered Cartesian grid. Higher order numerical schemes are used for time and spatial discretization. For the interface capturing, the level set method is selected. In order to test the generated waves...
The interaction of breaking waves with marine structures involves complex free surface deformatio... more The interaction of breaking waves with marine structures involves complex free surface deformation and instantaneous loading on the structural members. A typical offshore platform or a coastal structure consists of several vertical and horizontal members exposed to breaking wave action. The breaking wave hydrodynamics and the effect of neighbouring cylinders on multiple cylinders placed in near vicinity is important due to force amplification or reduction resulting from interaction between the cylinders. The kinematics of breaking waves and the hydrodynamics of breaking wave interaction with a single vertical cylinder have been studied in detail in current literature. Studies have established that the location of a cylinder with respect to the wave breaking point has a major influence on the breaking wave forces on the cylinder. These studies have to be extended to investigate the hydrodynamics of cylinders placed close to each other to understand the modifications in the force regi...
Scour and Erosion
Wave action stirs up sediments and keeps it in suspension while currents wash it away from the co... more 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 excessive sediment transport leading to the failure of hydraulic structures. In this study, numerical modeling of local scour under waves and current is carried out using the open source CFD model REEF3D, which solves the Navier-Stokes equation using the finite difference method. The simulated flow field from the Navier-Stokes equations is coupled with sediment transport algorithms in a numerical waves tank. Further, the calculated bedload and suspended load are linked with the Exner formula to calculate bed elevation changes. The free surface and scoured bed surface are captured using the level set method. Two case scenarios, namely scour under waves and scour under current are run until the equilibrium scour condition is achieved. The simulated results are compared with experimental data of Link (2006) and Sumer & Fredsoe (2001). Good comparison between experimental data and simulated results is observed. It is observed that for equal flow velocity in the flume, sediment transport under current only condition is larger than under waves alone.
Energy Procedia
Offshore wind turbine substructures consisting of cylindrical members are exposed to highly non-l... more Offshore wind turbine substructures consisting of cylindrical members are exposed to highly non-linear and breaking waves in shallow waters [1]. Those structures experience extreme impulsive loads of short duration from breaking waves that can cause permanent structural damage[2]. The main purpose of the present paper is to investigate the wave impact forces on a slender cylinder from plunging breaking waves in shallow waters both experimentally and numerically. The present study consists of two major parts: laboratory measurements and numerical simulations. The laboratory experiments are performed with regular waves. Plunging breaking waves are generated and free surface elevations are measured around the cylinder. Next, numerical simulations are carried out in the three-dimensional numerical wave tank REEF3D. The model is based on the incompressible Reynolds-averaged Navier-Stokes equations together with the k − ω for turbulence and the level set method for free surface. The numerical results are compared with the laboratory measurements in order to validate the numerical model. A good agreement between the computed results and the experimental data is seen for the breaking wave properties. Further, the breaking wave forces and the free surface deformations during the interaction of plunging breaking waves with a vertical cylinder are investigated and they are reasonably well represented in the numerical simulations.
International Journal of Offshore and Polar Engineering
Offshore structures are exposed to irregular sea states. It consists of breaking and non-breaking... more 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 is an important factor in the design of offshore structures. In the present study, a numerical investigation is performed to study steep irregular waves in deep water. The irregular waves are generated using the Torsethaugen spectrum which is a double-peaked spectrum defined for a locally fully developed sea. The Torsethaugen spectrum takes both the sea and swell waves into account. Thus, the generated waves can be very steep. The numerical investigation of such steep waves is quite challenging due to their high wave steepness and wave-wave interaction. The present investigation is performed using the open-source computational fluid dynamics (CFD) model. The wave generation and propagation of steep irregular waves in the numerical model is validated by comparing the numerical wave spectrum with the experimental input wave spectrum. The numerical results are in a good agreement with experimental results. The changes in the spectral wave density during the wave propagation are studied. Further, the double-hinged flap wavemaker is also tested and validated by comparing the numerical and experimental free surface elevation over time. The time and the frequency domain analysis is also performed to investigate the changes in the free surface horizontal velocity. Complex flow features during the wave propagation are well captured by the CFD model.
Journal of Offshore Mechanics and Arctic Engineering
The main purpose of the study is to investigate the breaking wave interaction with a group of fou... more The main purpose of the study is to investigate the breaking wave interaction with a group of four circular cylinders. The physical process of wave breaking involves many parameters, and an accurate numerical modeling of breaking waves and the interaction with a structure remain a challenge. In the present study, the open-source computational fluid dynamics (CFD) model REEF3D is used to simulate the breaking wave interaction with multiple cylinders. The numerical model is based on the incompressible Reynolds-averaged Navier–Stokes (RANS) equations, the level set method for the free surface, and the k–ω model for turbulence. The numerical model is validated with experimental data of large-scale experiments for the free surface elevation and the breaking wave force on a single cylinder. A good agreement is obtained between the numerical results and experimental data. Two different configurations with four cylinders are examined: in-line square configuration and diamond square configur...
International Journal of Offshore and Polar Engineering
Journal of Offshore Mechanics and Arctic Engineering
Wave loads from breaking waves on offshore wind turbine (OWT) substructures in shallow waters sti... more Wave loads from breaking waves on offshore wind turbine (OWT) substructures in shallow waters still remain uncertain. The interaction of breaking waves with structures is characterized by complex free surface deformations, instantaneous impact of the water mass against the structure, and consequently large wave forces on the structures. The main objective of the paper is to investigate wave impact pressures and kinematics during the interaction of breaking waves with a vertical cylinder using the open-source computational fluid dynamics (CFD) model REEF3D. The model is based on the Reynolds-averaged Navier–Stokes (RANS) equations coupled with the level set method and k–ω turbulence model. Three wave impact conditions are considered in this study. The numerically simulated free surface deformations around the cylinder during the breaking wave interaction are also presented for different wave impact conditions. For three wave impact conditions, the wave impact pressure and the horizon...
Volume 2: Prof. Carl Martin Larsen and Dr. Owen Oakley Honoring Symposia on CFD and VIV
Currents and waves cause flow-structure interaction problems in systems installed in the ocean. P... more Currents and waves cause flow-structure interaction problems in systems installed in the ocean. Particularly for bluff bodies, vortices form in the body wake, which can cause strong structural vibrations (Vortex-Induced Vibrations, VIV). The magnitude and frequency content of VIV is determined by the shape, material properties, and size of the bluff body, and the nature and velocity of the oncoming flow. Riser systems are extensively used in the ocean to drill for oil wells, or produce oil and gas from the bottom of the ocean. Risers often consist of a central pipe, surrounded by several smaller cylinders, including the kill and choke lines. We present a series of experiments involving forced in-line and cross flow motions of short rigid sections of a riser containing 6 symmetrically arranged kill and choke lines. The experiments were carried out at the MIT Towing Tank. We present a systematic database of the hydrodynamic coefficients, consisting of the forces in phase with velocity...
Journal of Offshore Mechanics and Arctic Engineering
On several occasions, freak waves have been observed in the past, some causing severe damage. In ... more On several occasions, freak waves have been observed in the past, some causing severe damage. In order to model such extreme wave conditions, one possibility is to use focused waves of first- or second-order based on irregular sea-state wave spectra. The wave phase is chosen such that the waves focus at a predetermined location and time, but the individual wave components become steep and start breaking before the focus location for large amplitudes. In this study, transient wave packets are used for extreme wave generation. Extreme waves are generated that are higher and only break at the concentration point using the transient wave packets method implemented in the open-source CFD model REEF3D. Model validation is performed by comparison to experimental results. The generation of wave packets with an 8.3 times shorter focus distance is investigated and the wave is replicated in a shorter domain with a 9% higher crest. The method is further used to generate a steepness induced-brea...
Journal of Offshore Mechanics and Arctic Engineering
Harbors are important infrastructures for an offshore production chain. These harbors are protect... more Harbors are important infrastructures for an offshore production chain. These harbors are protected from the actions of sea by breakwaters to ensure safe loading, unloading of vessels and also to protect the infrastructure. In current literature, research regarding the design of these structures is majorly based on physical model tests. In this study a new tool, a three-dimensional (3D) numerical model is introduced. The open-source computational fluid dynamics (CFD) model REEF3D is used to study the design of berm breakwaters. The model uses the Volume-averaged Reynolds-averaged Navier-Stokes (VRANS) equations to solve the porous flows. At first, the VRANS approach in REEF3D is validated for flow through porous media. A dam break case is simulated and comparisons are made for the free surface both inside and outside the porous medium. The numerical model REEF3D is applied to show how to extend the database obtained with purely numerical results, simulating different structural alte...
Journal of Waterway, Port, Coastal, and Ocean Engineering
The interaction of plunging breaking waves with a pair of cylinders placed in tandem is investiga... more The interaction of plunging breaking waves with a pair of cylinders placed in tandem is investigated using the open-source computational fluid dynamics (CFD) model REEF3D. The model is validated using experimental data for total wave forces and free surface elevations for breaking wave interaction with a single cylinder. Wave interaction with tandem cylinders is investigated for four different wave impact scenarios on the first cylinder and six different distances between the cylinders in each scenario. Wave forces on the upstream cylinder are generally found to be less than the forces on a single cylinder for a particular scenario. The force on the downstream cylinder is lower than the force on the upstream cylinder when the breaker tongue impacts the first cylinder. Under conditions where the breaker tongue impacts the downstream cylinder around the wave crest level, the wave force on the downstream cylinder is higher than the force on the upstream cylinder. The wave forces experienced by the tandem cylinders is highly influenced by the location of the breaking point with respect to the cylinders and the distance between the cylinders.
Engineering Applications of Computational Fluid Mechanics
Wave propagation over a submerged bar is simulated using the open source CFD model REEF3D with va... more Wave propagation over a submerged bar is simulated using the open source CFD model REEF3D with various incident wave heights to study shoaling, wave breaking features and the process of wave decomposition into higher harmonics for relatively long waves of kd = 0.52. The computed free surface elevations are compared with experimental data and good agreement is obtained for both non-breaking and spilling breaking waves for both the wave phase and free surface elevation, which has been difficult to obtain in current literature. The differences in the mode of wave shoaling over the weather side slope and the wave decomposition over the lee side slope of the submerged bar are discussed. The evolution of spilling breakers and plunging breakers over the bar crest is also studied. It is found that the free surface elevation continuously increases due to shoaling in the case of non-breaking waves, whereas breaking waves propagate with much lower free surface elevations after breaking over the bar crest. The power spectra of the free surface elevations at various locations indicate that the wave energy in the fundamental frequency is reduced by 76% for the non-breaking wave with kA = 0.015 and by about 90% in other cases with higher incident wave heights with kA = 0.023−0.034 due to energy dissipation and energy transfer to higher harmonic components as the wave propagates over the submerged bar.
Journal of Waterway, Port, Coastal, and Ocean Engineering
Journal of Offshore Mechanics and Arctic Engineering
Many offshore constructions and operations involve water impact problems such as water slamming o... more Many offshore constructions and operations involve water impact problems such as water slamming onto a structure or free fall of objects with subsequent water entry and emergence. Wave slamming on semisubmersibles, vertical members of jacket structures, crane operation of a diving bell, and dropping of free fall lifeboats are some notable examples. The slamming and water entry problems lead to large instantaneous impact pressures on the structure, accompanied with complex free surface deformations. These need to be studied in detail in order to obtain a better understanding of the fluid physics involved and develop safe and economical design. Numerical modeling of a free falling body into water involves several complex hydrodynamic features after its free fall such as water entry, submergence into water and resurfacing. The water entry and submergence lead to formation of water jets and air cavities in the water resulting in large impact forces on the object. In order to evaluate th...
Journal of Offshore Mechanics and Arctic Engineering
For the stability of offshore structures, such as offshore wind foundations, extreme wave conditi... more For the stability of offshore structures, such as offshore wind foundations, extreme wave conditions need to be taken into account. Waves from extreme events are critical from the design perspective. In a numerical wave tank, extreme waves can be modeled using focused waves. Here, linear waves are generated from a wave spectrum. The wave crests of the generated waves coincide at a preselected location and time. Focused wave generation is implemented in the numerical wave tank module of REEF3D, which has been extensively and successfully tested for various wave hydrodynamics and wave–structure interaction problems in particular and for free surface flows in general. The open-source computational fluid dynamics (CFD) code REEF3D solves the three-dimensional Navier–Stokes equations on a staggered Cartesian grid. Higher order numerical schemes are used for time and spatial discretization. For the interface capturing, the level set method is selected. In order to test the generated waves...