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Title: Experiments for Waves Breaking Over a Three-Dimensional Submerged Bar.
Creator: Roy, Travis L., Seiffert, Betsy, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The influence of monochromatic waves interacting with a submerged bar structure is investigated through laboratory experiments in a wave flume. Wave profiles for a range of non-breaking, spilling, and plunging waves were analyzed for three offshore water depths through the interpretation of wave gauge and video imagery data. Evolution of propagating waves was reflected in data which showed increased amplitudes due to shoaling with subsequent breaking, transfer of single frequency spectrum...
Show moreThe influence of monochromatic waves interacting with a submerged bar structure is investigated through laboratory experiments in a wave flume. Wave profiles for a range of non-breaking, spilling, and plunging waves were analyzed for three offshore water depths through the interpretation of wave gauge and video imagery data. Evolution of propagating waves was reflected in data which showed increased amplitudes due to shoaling with subsequent breaking, transfer of single frequency spectrum from lower to higher frequency harmonics, and dissipation of energy after breaking onset. Comparisons of collected experimental data with previous theory developed by Yao et al (2013), Smith & Kraus (1991), Galvin (1968) for wave classification showed to be relatively accurate for both relative submergence and surf similarity methods. Wave breaking onset identified by instability in the wave crests allowed for measurements of breaking wave height and depth at breaking. Theory by Johnson (2006) and Goda (1974) compared to experimental data showed little agreement for predicting breaking wave heights.
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Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013096
Subject Headings: Water waves., Water waves--Measurement., Surface waves.
Format: Document (PDF)

Title: Wave attenuation by rigid and flexible-membrane submerged breakwaters.
Creator: Harris, Lee Errol., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This research investigates the use of rigid and flexible-membrane submerged breakwaters for wave energy attenuation. A comprehensive review of breakwater design criteria and previous research on submerged breakwaters is included. Physical model laboratory studies conducted by the author and other researchers are investigated as a means for obtaining formulations for wave transmission coefficients. The mechanisms by which waves are attenuated and break are analyzed using video photography of...
Show moreThis research investigates the use of rigid and flexible-membrane submerged breakwaters for wave energy attenuation. A comprehensive review of breakwater design criteria and previous research on submerged breakwaters is included. Physical model laboratory studies conducted by the author and other researchers are investigated as a means for obtaining formulations for wave transmission coefficients. The mechanisms by which waves are attenuated and break are analyzed using video photography of the wave tank tests. The primary objective of this doctoral research was to determine and compare the wave attenuation of non-conventional rigid and flexible-membrane type submerged breakwaters. Physical model tests were performed using the wave tank facilities at Florida Institute of Technology located in Melbourne, Florida. Six different breakwater cross-sections used were: (1) rectangular, (2) triangular, (3) P.E.P.-$Reef\sp{TM}$, (4) single sand-filled container, (5) three stacked sand-filled containers, and (6) one single water-filled container. The first three breakwater units were rigid (or monolithic), and the last three units are flexible-membrane breakwater units. All six units tested had the same height, length (longshore), and base width (cross-shore), with different cross-sections and shapes, and were composed of different materials. A new classification scheme was developed for breakwaters and artificial reefs, based on water depth, structure height, and wave heights. The wave-structure interaction resulting in the wave breaking on the submerged breakwaters was documented, and the observations were analyzed. Wave transmission coefficients were computed for the six different breakwater models tested, and comparisons between the different models were made. Conclusions regarding the primary factors affecting the effectiveness of rigid and flexible-membrane submerged breakwaters were developed, as were recommendations for further research.
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Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/12468
Subject Headings: Breakwaters, Water waves
Format: Document (PDF)

Title: EXPERIMENTAL INVESTIGATION ON WAVE BREAKING AND TRANSMISSION IN SUBMERGED ARTIFICIAL REEFS.
Creator: Raju, Rahul Dev, Arockiasamy, Madasamy, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
Abstract/Description: Artificial reefs are coastal structures built to improve marine life and prevent beach erosion. During earlier days artificial reefs were constructed for recreational fishing using discarded scraps and waste materials. Later on, ships were scuttled for constructing artificial reefs. Artificial reefs dissipate the energy of the wave by making the wave break over the reef. The artificial reefs used for coastal protection are usually in submerged condition as this condition does not affect the...
Show moreArtificial reefs are coastal structures built to improve marine life and prevent beach erosion. During earlier days artificial reefs were constructed for recreational fishing using discarded scraps and waste materials. Later on, ships were scuttled for constructing artificial reefs. Artificial reefs dissipate the energy of the wave by making the wave break over the reef. The artificial reefs used for coastal protection are usually in submerged condition as this condition does not affect the aesthetic beauty of the beach. Wave transmission decides the efficiency of submerged-detached artificial reef in protecting the beach from the incoming waves. The efficiency of submerged detached coastal protection structures in protecting the beach is usually measured in terms of wave transmission coefficient. The experimental investigation in the present study is carried out for submerged two-dimensional impermeable and permeable reefs for three water depths. The crest width of the reefs considered for the experimental studies are 60 cm and 20 cm. The permeable artificial reefs are made up of oyster shells in Nylon bags and biodegradable bags. The water levels considered for the study are 35 cm, 34 cm, and 33 cm. The effect of pore space between the oyster shells, crest width, water depth and wave parameters on the wave transmission coefficient for submerged impermeable and permeable artificial reefs are studied experimentally. The wave transmission coefficient is calculated for submerged impermeable and permeable reefs for different water levels and crest widths. Based on the results of the present experimental studies, it is logical to conclude that both submerged impermeable and permeable artificial reefs contribute to a significant extent to the attenuation of the incident wave.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014241
Subject Headings: Artificial reefs, Water waves, Ocean waves
Format: Document (PDF)

Title: LABORATORY SIMULATION OF LIFE RAFT DRIFT.
Creator: VELIOTIS, JOANNA., Florida Atlantic University, Hotchkiss, Frances S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Laboratory experiments to provide a better understanding of the dynamics of drifting life rafts were conducted in an outdoor, above ground wave tank which measures 48 feet 10 inches in length, 23 feet 7 inches in width and has a depth of 24 inches. Vessel models were subjected to fan generated wind and waves created by a hinged wave paddle and their leeway was recorded and analyzed. The models were found to move so that wind and wave forces remained balanced. The life raft drag coefficients...
Show moreLaboratory experiments to provide a better understanding of the dynamics of drifting life rafts were conducted in an outdoor, above ground wave tank which measures 48 feet 10 inches in length, 23 feet 7 inches in width and has a depth of 24 inches. Vessel models were subjected to fan generated wind and waves created by a hinged wave paddle and their leeway was recorded and analyzed. The models were found to move so that wind and wave forces remained balanced. The life raft drag coefficients found are of the same order of magnitude as those ascertained in the numerical modelling of the same experiments.
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Date Issued: 1986
PURL: http://purl.flvc.org/fcla/dt/14347
Subject Headings: Life rafts, Winds, Water waves
Format: Document (PDF)

Title: Computation of hydrodynamic coefficients and determination of dynamic stability characteristics of an underwater vehicle including free surface effects.
Creator: Saout, Olivier., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The inviscid hydrodynamic coefficients of an underwater vehicle (Ocean EXplorer), including the nonlinear effects of the wave surface, are computed using a boundary-integral method. A mixed Eulerian-Lagrangian formulation (Longuet-Higgins and Cokelet, 1976) is used for the treatment of nonlinear free-surface conditions. The algorithm is validated using the work-energy theorem (Yeung, 1982) and experimental data. Results, in the form of free-surface elevations and hydrodynamic coefficients,...
Show moreThe inviscid hydrodynamic coefficients of an underwater vehicle (Ocean EXplorer), including the nonlinear effects of the wave surface, are computed using a boundary-integral method. A mixed Eulerian-Lagrangian formulation (Longuet-Higgins and Cokelet, 1976) is used for the treatment of nonlinear free-surface conditions. The algorithm is validated using the work-energy theorem (Yeung, 1982) and experimental data. Results, in the form of free-surface elevations and hydrodynamic coefficients, are obtained for a range of body geometries and maneuvers. The open-loop dynamics of underwater vehicles are then investigated by solving the 3DOF rigid-body equations of motion (OXY plane). The advantages and possible usage of the developed methodology for the design and control of underwater vehicles, as well as topics for further research, are addressed in the conclusion chapter of the thesis.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/12981
Subject Headings: Hydrodynamics, Oceanographic submersibles, Water waves
Format: Document (PDF)

Title: Simulation of grain-size abundances on a barred upper shoreface.
Creator: Liu, James T., Zarillo, Gary A., Harbor Branch Oceanographic Institute
Date Issued: 1993
PURL: http://purl.flvc.org/FCLA/DT/3353876
Subject Headings: Banks (Oceanography), Water waves, Sedimentation and deposition
Format: Document (PDF)

Title: HYDRODYNAMIC PERFORMANCE OF AN UNMANNED CATAMARAN VEHICLE IN HEAD SEAS.
Creator: Prasad, Bijoy, Dhanak, Manhar, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: This study analyzes the hydrodynamic performance of an advanced catamaran vehicle using computational fluid dynamics (CFD) simulations and experimental testing data in support of system identification and development of a physics-based control system for unmanned surface vehicle (USV) operations in coastal waters. A series of steps based on increasing complexity are considered sequentially in this study. First the steady flow past the static vehicle, then the vehicle with a fixed orientation...
Show moreThis study analyzes the hydrodynamic performance of an advanced catamaran vehicle using computational fluid dynamics (CFD) simulations and experimental testing data in support of system identification and development of a physics-based control system for unmanned surface vehicle (USV) operations in coastal waters. A series of steps based on increasing complexity are considered sequentially in this study. First the steady flow past the static vehicle, then the vehicle with a fixed orientation advancing in calm water, and finally the vehicle moving with two degrees of freedom (DOF) in calm water as well as head seas. The main objective of the study is to assess the role of general multiphase unsteady Reynolds Averaged Navier Stokes (RANS) as a predictive tool for the hydrodynamic performance of an USV. A parametric analysis of the vehicle performance at different Froude number and wave steepness in shallow waters is conducted. The characteristics of the wave resistance, heaving and pitching motion, wave-hull interactions, and free surface flow patterns are investigated. The study will aid in the design of a robust physics-based control system for the vehicle and provide a tool for prediction of its performance.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013404
Subject Headings: Catamarans, Computational fluid dynamics, Water waves
Format: Document (PDF)

Title: Performance Enhancement of an ACV in Varying Water Depth.
Creator: Kouvaras, Nicholas, Dhanak, Manhar R., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This research focuses on the study of the behavior of a high speed vehicle and particularly an air-cushion vehicle (ACV) in varying bathymetry. An extensive data acquisition system is developed to gather data during the experiments. Four groups of experiments are conducted in a wave tank using a scale model surface effect ship to generate a database that is post processed to assess phenomena under various conditions. Group No1 experiments involved characterizing the wave motion in the tank in...
Show moreThis research focuses on the study of the behavior of a high speed vehicle and particularly an air-cushion vehicle (ACV) in varying bathymetry. An extensive data acquisition system is developed to gather data during the experiments. Four groups of experiments are conducted in a wave tank using a scale model surface effect ship to generate a database that is post processed to assess phenomena under various conditions. Group No1 experiments involved characterizing the wave motion in the tank in the absence of the vehicle as the waves transformed in response to variation in water depth. Based on these experimental datasets, the wave breaking type and position are predicted using a machine learning approach and, more specifically, a neural network of the multilayer perceptron type. Group No2 experiments are in support of a parametric study to evaluate the vehicle's performance under calm water conditions when the control inputs are varied. A system identific ation approach based on the experimental data is proposed to create a model that predicts the vehicles translational motion. In group No3 the experiments involve the vehicle travelling with a non-zero forward speed and encountering transforming head and following seas. Transient and non-linear phenomena and relations among parameters are observed Group No 4 experiments involve the vehicle maintaining a position in the "surf-zone" under manual control, encountering breaking waves that break on its bow skirt. Non-linear phenomena are discussed based on the experimental results.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004514, http://purl.flvc.org/fau/fd/FA00004514
Subject Headings: Wave motlion, Theory of., Water waves--Measurement., Ground-effect machines.
Format: Document (PDF)

Title: Dynamic analysis of single- and multi-module platforms in waves.
Creator: Kling, Kaylie Ann., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The response of single- and multi-module floating platforms to surface waves is investigated theoretically. Wave exciting forces are computed using methods based on the Morrison equation and Froude-Krylov hypothesis. The radiation forces are obtained from experimental results of Vugt and where possible diffraction forces using the Haskind reciprocity relation. Heave and pitch response of a one-module platform and hinge-connected two-module platform are determined by integrating the...
Show moreThe response of single- and multi-module floating platforms to surface waves is investigated theoretically. Wave exciting forces are computed using methods based on the Morrison equation and Froude-Krylov hypothesis. The radiation forces are obtained from experimental results of Vugt and where possible diffraction forces using the Haskind reciprocity relation. Heave and pitch response of a one-module platform and hinge-connected two-module platform are determined by integrating the corresponding equations of rigid-body motion. A structural dynamic analysis is also carried out using the Green's function method to determine the elastic flexural response of the platform to waves. The results are compared with the experimental and numerical findings of others. The thesis contributes to a better understanding of rigid-body and elastic response of large ocean platforms subject to wave forces. The methodology is computationally less intensive and therefore can be effectively used for the design of platforms and the validation of numerical algorithms.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13399
Subject Headings: Ocean engineering, Wave motion, Theory of, Water waves--Mathematical models, Drilling platforms, Extreme value theory
Format: Document (PDF)

Title: Low frequency nearshore current fluctuations on Florida’s central east coast.
Creator: Zweck, O. V., Hale, D. A., Harbor Branch Oceanographic Institute
Date Issued: 1979
PURL: http://purl.flvc.org/FCLA/DT/3183150
Subject Headings: Water currents, Tidal currents, Ocean waves--Analysis
Format: Document (PDF)

Title: Wave Ship Interaction in Transforming Seas.
Creator: Gong, Fuxian, Dhanak, Manhar R., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In near-shore transforming seas, as waves approach the shoreline, wave shoaling and sometimes wave breaking take place due to the decreasing water depth. When a ship advances through the transforming seas, the ship body and waves interact with each other substantially and can lead to unknown motions of the ship hull. The physical process of how the wave transforms in the surf zone and how the vehicle actually behaves when it passes through the transforming seas is a complicated issue that...
Show moreIn near-shore transforming seas, as waves approach the shoreline, wave shoaling and sometimes wave breaking take place due to the decreasing water depth. When a ship advances through the transforming seas, the ship body and waves interact with each other substantially and can lead to unknown motions of the ship hull. The physical process of how the wave transforms in the surf zone and how the vehicle actually behaves when it passes through the transforming seas is a complicated issue that triggers considerable research interest. The goal of my research is to characterize the dynamics of a high-speed surface ship model in transforming seas through a parametric numerical study of the shipwave interactions. In this study, the vehicle of interest is a surface effect ship (SES) and we aim to contribute to developing a methodology for simulating the transforming wave environment, including wave breaking, and its interactions with the SES. The thesis work uses a commercial software package ANSYS Fluent to generate numerical waves and model the interface between water and air using the volume of fluid (VoF) method. A ship motion solver and the dynamic mesh are used to enable the modeled ship to perform three degree-of-freedom (DoF) motion and the near-region of the ship hull to deform as well as re-mesh. Non-conformal meshes with hybrid compositions of different cell types and various grid sizes are used in the simulations for different purposes. Five user-defined functions (UDFs) are dynamically linked with the flow solver to incorporates ship/grid motions, wave damping and output of the numerical results. A series of steps were taken sequentially: 1) validation for ship motions including simulation of a static Wigley hull under steady flows to compare against previous experimental results by other researchers, and the comparison between the static SES model under steady flows and the moving SES model advancing in the calm water; 2) study of the ship with 3 DoF advancing in calm water of both constant depth and varying depth; 3) validation for numerical waves, including predictions of numerically progressive waves in both a regular tank and a tank with a sloped fringing reef to compare with theoretical and experimental results, respectively; 4) investigation of the transforming characteristics of the wave traveling over the sloped fringing reef, which mimics the near-shore wave environment and a study of the dynamics of the SES through transforming waves. We find that the flow solver used in this study reliably models the wave profiles along the ship hull. The comparison between a static SES in a current and a moving SES in calm water at the same Froude number shows that although the velocity fields around the vehicle are significantly different, the wave profiles inside and outside the rigid cushion of the vehicle are similar and the resistance force experienced by the vehicle in the two scenarios agree well over time. We conducted five numerical simulations of the vehicle traveling from shallow water to deep water across the transition zone for different Froude numbers. From the results, we find that as the Froude number increases, the wave resistance force on the vehicle becomes larger in both shallow water and deep water. In addition, the overall mean resistance force experienced by the vehicle over the whole trip increases with the Froude number. Statistical analysis of the wave motions suggests that the energy flux decreases dramatically in the onshore direction as the waves break. The more severe the wave-breaking process, the greater the decrease in energy flux. Both the increase of Froude number and the wave steepness apparently increase the resistance force on the vehicle in the shallow water. This thesis work captures the impact of the transforming characteristics of the waves and closely replicates the behavior of how waves interact with a ship in transforming seas through numerical modeling and simulation.
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Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004916, http://purl.flvc.org/fau/fd/FA00004916
Subject Headings: Hydrodynamics--Mathematical models., Fluid dynamics--Mathematical models., Ocean waves--Measurement., Water waves--Measurement., Coastal engineering.
Format: Document (PDF)

Title: Systems Identification and Control of an Autonomous Amphibious Vehicle: Experimental Testing & Control Model Validation for an Autonomous Cargo Transport Navy Vehicle.
Creator: Marquardt, Joseph G., von Ellenrieder, Karl, Graduate College
Date Issued: 2011-04-08
PURL: http://purl.flvc.org/fcla/dt/3172438
Subject Headings: Motor vehicles, Amphibious--United States, Water waves, Sea-power --United States
Format: Document (PDF)

Title: Design and analysis of hybrid titanium-composite hull structures under extreme wave and slamming loads.
Creator: Rahman, Md Hafizur, Mahfuz, Hassan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A finite element tool has been developed to design and investigate a multi-hull composite ship structure, and a hybrid hull of identical length and beam. Hybrid hull structure is assembled by Titanium alloy (Ti-6Al-4V) frame and sandwich composite panels. Wave loads and slamming loads acting on both hull structures have been calculated according to ABS rules at sea state 5 with a ship velocity of 40 knots. Comparisons of deformations and stresses between two sets of loadings demonstrate that...
Show moreA finite element tool has been developed to design and investigate a multi-hull composite ship structure, and a hybrid hull of identical length and beam. Hybrid hull structure is assembled by Titanium alloy (Ti-6Al-4V) frame and sandwich composite panels. Wave loads and slamming loads acting on both hull structures have been calculated according to ABS rules at sea state 5 with a ship velocity of 40 knots. Comparisons of deformations and stresses between two sets of loadings demonstrate that slamming loads have more detrimental effects on ship structure. Deformation under slamming is almost one order higher than that caused by wave loads. Also, Titanium frame in hybrid hull significantly reduces both deformation and stresses when compared to composite hull due to enhancement of in plane strength and stiffness of the hull. A 73m long hybrid hull has also been investigated under wave and slamming loads in time domain for dynamic analysis.
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Date Issued: 2013
PURL: http://purl.flvc.org/fau/fd/FA0004048
Subject Headings: Hulls (Naval architecture) -- Design and construction, Ships -- United States -- Design and construction, Structural dynamics, Water waves -- Mathematical models
Format: Document (PDF)

FAU Theses and Dissertations (10)	+ -
HBOI Faculty Contributions (2)	+ -
FAU Graduate Student Research (1)	+ -

Water waves (7)	+ -
Water waves--Measurement. (3)	+ -
Artificial reefs (1)	+ -
Banks (Oceanography) (1)	+ -
Breakwaters (1)	+ -

Catamarans (1)	+ -
Coastal engineering. (1)	+ -
Computational fluid dynamics (1)	+ -
Drilling platforms (1)	+ -
Extreme value theory (1)	+ -
Fluid dynamics--Mathematical models. (1)	+ -
Ground-effect machines. (1)	+ -
Hulls (Naval architecture) -- Design and construction (1)	+ -
Hydrodynamics (1)	+ -
Hydrodynamics--Mathematical models. (1)	+ -
Life rafts (1)	+ -
Motor vehicles, Amphibious--United States (1)	+ -
Ocean engineering (1)	+ -
Ocean waves (1)	+ -
Ocean waves--Analysis (1)	+ -
Ocean waves--Measurement. (1)	+ -
Oceanographic submersibles (1)	+ -
Sea-power --United States (1)	+ -
Sedimentation and deposition (1)	+ -
Ships -- United States -- Design and construction (1)	+ -
Structural dynamics (1)	+ -
Surface waves. (1)	+ -
Tidal currents (1)	+ -
Water currents (1)	+ -
Water waves -- Mathematical models (1)	+ -

Electronic Thesis or Dissertation (10)	+ -
article (2)	+ -
abstract (1)	+ -

College of Engineering and Computer Science (10)	+ -
Department of Ocean and Mechanical Engineering (9)	+ -
Florida Atlantic University (9)	+ -
Ananthakrishnan, Palaniswamy (2)	+ -
Dhanak, Manhar R. (2)	+ -

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