Current Search:  Marine engineering. (x)

View All Items

  • CSV Spreadsheet
(1 - 11 of 11)
SHIP MOTION PREDICTION USING AUTO REGRESSIVE MOVING AVERAGE METHOD (NAVAL ARCHITECTURE, OFFSHORE TECHNOLOGY, DYNAMIC POSITIONING)
Title
SHIP MOTION PREDICTION USING AUTO REGRESSIVE MOVING AVERAGE METHOD (NAVAL ARCHITECTURE, OFFSHORE TECHNOLOGY, DYNAMIC POSITIONING).
Creator
CHANDRASEKHARAN, CHANDRAMOHAN., Florida Atlantic University, Lin, Newman K.
Abstract/Description
The time series method of Auto Regressive Moving Average (ARMA) is applied to the problem of real time ship motion prediction. The theory of Scalar input Scalar output ARMA (n, n-1) model and the same extended to multiple series as vector, ARMAV model have been concisely presented. The field experimental procedure for roll measurement of vessel at sea and barge model test procedure for heave and pitch measurements are discussed. The time series data of roll is analysed as a scalar ARMA (n, n...
Show moreThe time series method of Auto Regressive Moving Average (ARMA) is applied to the problem of real time ship motion prediction. The theory of Scalar input Scalar output ARMA (n, n-1) model and the same extended to multiple series as vector, ARMAV model have been concisely presented. The field experimental procedure for roll measurement of vessel at sea and barge model test procedure for heave and pitch measurements are discussed. The time series data of roll is analysed as a scalar ARMA (n, n-1) model and the results of prediction are presented. The model test data of heave, pitch and wave were analysed as ARMAV (n,n-1) vector model and the results are presented. The model test and experimental results demonstrate the feasibility of ARMA modeling procedure as a valuable tool in the area of real time ship motion prediction.
Show less
Date Issued
1985
PURL
http://purl.flvc.org/fcla/dt/14246
Subject Headings
Motion study, Marine engineering
Format
Document (PDF)
Extended range underwater optical imaging architecture
Title
Extended range underwater optical imaging architecture.
Creator
Dalgleish, Fraser R., Caimi, F. M., Mazel, C. H., Glynn, J. M.
Date Issued
2006-09-18 - 2006-09-21
PURL
http://purl.flvc.org/FCLA/DT/1927692
Subject Headings
Underwater imaging systems, Imaging systems, Marine engineering
Format
Document (PDF)
Validation of numerical modelling for long range acoustic propagation
Title
Validation of numerical modelling for long range acoustic propagation.
Creator
Riley, Joseph M., Florida Atlantic University, Glegg, Stewart A. L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Laboratory scale measurements were conducted to validate numerical prediction models used to predict the acoustic field in a shallow water ocean environment. Experimental measurements were conducted in a range independent environment which included the effects of shear in marine sediments and in a depth varying range dependent environment. Good agreement between the experimental measurements and the numerical prediction codes were obtained using optimized values for the input parameters of...
Show moreLaboratory scale measurements were conducted to validate numerical prediction models used to predict the acoustic field in a shallow water ocean environment. Experimental measurements were conducted in a range independent environment which included the effects of shear in marine sediments and in a depth varying range dependent environment. Good agreement between the experimental measurements and the numerical prediction codes were obtained using optimized values for the input parameters of the environmental model. In comparing experimental measurements to the numerical prediction codes it became apparent that the codes were very sensitive to the input parameters describing the bottom boundary of the ocean waveguide.
Show less
Date Issued
1992
PURL
http://purl.flvc.org/fcla/dt/14819
Subject Headings
Acoustical engineering, Underwater acoustics, Marine sediments
Format
Document (PDF)
SMALL UNMANNED MARINE HYDROKINETIC PLATFORMS FOR POWER GENERATION IN COASTAL AND TIDAL WATERS
Title
SMALL UNMANNED MARINE HYDROKINETIC PLATFORMS FOR POWER GENERATION IN COASTAL AND TIDAL WATERS.
Creator
McKinney, Adriana, Dhanak, Manhar, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description
The feasibility and optimization of small unmanned mobile marine hydrokinetic (MHK) energy platforms for harvesting marine current energy in coastal and tidal waters are examined. A case study of a platform based on the use of a free-surface waterwheel (FSWW) mounted on an autonomous unmanned surface vehicle (USV) was conducted. Such platforms can serve as recharging stations for aerial drones (UAVs), enabling extension of the UAVs’ autonomous operating time. An unmanned MHK platform...
Show moreThe feasibility and optimization of small unmanned mobile marine hydrokinetic (MHK) energy platforms for harvesting marine current energy in coastal and tidal waters are examined. A case study of a platform based on the use of a free-surface waterwheel (FSWW) mounted on an autonomous unmanned surface vehicle (USV) was conducted. Such platforms can serve as recharging stations for aerial drones (UAVs), enabling extension of the UAVs’ autonomous operating time. An unmanned MHK platform potentially meets this need with sustainable power harvested from water currents. For the case study, six different waterwheel configurations were field-tested in the Intracoastal Waterway of South Florida in support of determining the configuration that produced the most power. Required technologies for unmanned operations of the MHK platform were developed and tested. The data from the field-testing were analyzed to develop an empirical relation between the wheel’s theoretical hydrokinetic power produced and the mechanical power harnessed by the MHK platform with various waterwheel configurations during field-testing. The field data was also used to determine the electrical power generated by the FSWW configurations during field-testing. The study has led to the development of standardized testing procedures. The empirical relation is used to examine predicted power production through scaling up different physical aspects of the waterwheel.
Show less
Date Issued
2024
PURL
http://purl.flvc.org/fau/fd/FA00014412
Subject Headings
Ocean engineering, Renewable energy, Marine turbines
Format
Document (PDF)
Thrust Response of a Vectored-Thruster Unmanned Underwater Vehicle
Title
Thrust Response of a Vectored-Thruster Unmanned Underwater Vehicle.
Creator
Ackermann, Lloyd E. J., von Ellenrieder, Karl, Florida Atlantic University
Abstract/Description
Towing tank/water flume experiments are conducted to characterize the dynamics of a Remotely-Piloted Unmanned Underwater Vehicle (RPUUV) propelled by a vectored-thruster system. Force and torque measurements are used to determine the coefficients of drag, lift, yaw-moment and thrust of the vehicle as a function of the vehicle yaw angle and the vectored-thruster rudder angle. Simultaneously, particle Image Velocimetry (PIV) measurements of the propeller inlet flow are also performed to examine...
Show moreTowing tank/water flume experiments are conducted to characterize the dynamics of a Remotely-Piloted Unmanned Underwater Vehicle (RPUUV) propelled by a vectored-thruster system. Force and torque measurements are used to determine the coefficients of drag, lift, yaw-moment and thrust of the vehicle as a function of the vehicle yaw angle and the vectored-thruster rudder angle. Simultaneously, particle Image Velocimetry (PIV) measurements of the propeller inlet flow are also performed to examine the variation of flow conditions at the propeller inlet with rudder angle. The tests are conducted at 0.150 rnls, 0.300 rnls, 0.515 rnls and 0.773 rnls. While the measured drag coefficient is slightly higher than predicted by theory at low Reynolds number (1.44 x10^5 and 2.88 x10^5), the hydrodynamic coefficients data are expected to be useful in predicting the response of vehicles in the field. Additionally, the magnitude of the thrust vector varies nonlinearly with rudder angle and for nonzero rudder angles the thrust vector does not point in the same direction as the thruster axis.
Show less
Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00012500
Subject Headings
Naval architecture, Oceanographic submersibles--Hydrodynamics, Vibration (Marine engineering)
Format
Document (PDF)
Transport of seawater and its influence on the transverse tensile strength of unidirectional composite materials
Title
Transport of seawater and its influence on the transverse tensile strength of unidirectional composite materials.
Creator
Fichera, Maryann, Carlsson, Leif A., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The objective of this research was to characterize the seawater transport and its effect on the transverse tensile strength of a carbon/vinylester composite. The moisture contents of neat vinylester and unidirectional carbon/vinylester composite panels immersed in seawater were monitored until saturation. A model for moisture up-take was developed based on superposition of Fickian diffusion, and Darcy’s law for capillary transport of water. Both the predicted and measured saturation times...
Show moreThe objective of this research was to characterize the seawater transport and its effect on the transverse tensile strength of a carbon/vinylester composite. The moisture contents of neat vinylester and unidirectional carbon/vinylester composite panels immersed in seawater were monitored until saturation. A model for moisture up-take was developed based on superposition of Fickian diffusion, and Darcy’s law for capillary transport of water. Both the predicted and measured saturation times increased with increasing panel size, however the diffusion model predicts much longer times while the capillary model predicts shorter time than observed experimentally. It was also found that the saturation moisture content decreased with increasing panel size. Testing of macroscopic and miniature composite transverse tensile specimens, and SEM failure inspection revealed more fiber/matrix debonding in the seawater saturated composite than the dry composite, consistent with a slightly reduced transverse tensile strength.
Show less
Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004368, http://purl.flvc.org/fau/fd/FA00004368
Subject Headings
Composite materials -- Deterioration, Composite materials -- Effect of environment on, Engineering design, Marine engineering, Polymers -- Permeability, Polymetric composites -- Deterioration
Format
Document (PDF)
Propulsive Performance and Maneuver Control of Undulatory Ribbon Fin Propulsion Using Bio-inspired Robotic Systems
Title
Propulsive Performance and Maneuver Control of Undulatory Ribbon Fin Propulsion Using Bio-inspired Robotic Systems.
Creator
Liu, Hanlin, Curet, Oscar M., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Undulatory ribbon- n-based propulsion is an appealing propulsion mechanism due to its rich locomotor capabilities that can improve the propulsive performance and maneuverability of underwater vehicles. For instance, the swimming mechanics of weakly electric black ghost knife sh (Apteronotus albifrons) is of great interest to study because of their high swimming e ciency at low speeds and extraordinary agility such as rapid reversal swimming, hovering in presence of water disturbance, rolling...
Show moreUndulatory ribbon- n-based propulsion is an appealing propulsion mechanism due to its rich locomotor capabilities that can improve the propulsive performance and maneuverability of underwater vehicles. For instance, the swimming mechanics of weakly electric black ghost knife sh (Apteronotus albifrons) is of great interest to study because of their high swimming e ciency at low speeds and extraordinary agility such as rapid reversal swimming, hovering in presence of water disturbance, rolling and vertical swimming. In this thesis work, to facilitate our understanding on the exible undulatory ribbon n propulsion, we have four research motivations. The rst objective is to study how the use of exible rays and di erent n morphology can in uence the propulsive performance of ribbon- n propulsion. It is possible that natural swimmers using this locomotion method could take advantage of passive n motion based on the coupling of uid-structure interaction and the elasto-mechanical responses of the undulating n. Therefore, the second objective is to understand how an under-actuated undulating n can take advantage of natural dynamics of the uid-structure interaction for the propulsive force generation. In addition to the impressive propulsive performance of the undulatory n propulsion, the exceptional maneuverability of knife sh is also a key motivation that drives this thesis work. Thus, we dedicate to investigate how traveling wave shapes and actuation parameters (frequency, wavelength) can manipulate the maneuvering behaviors of a swimmer propelled by an undulating ribbon n. Lastly, we aim to uncover the e ect of varying traveling wave amplitudes and pectoral ns on its maneuvering performances. Two robotic devices were developed to study the propulsive performance of both fullyactuated and under-actuated ribbon n propulsion and investigate the maneuver control of a free-swimming underwater robot propelled by an undulatory n. For the rst research aim, we study the e ect of exible rays and di erent n morphology on the propulsive performance of ribbon- n propulsion. A physical model composed of fteen rays interconnected with an elastic membrane was used to test four di erent ray exural sti ness and four aspect ratios. Our results show that exible rays can improve the propulsive e ciency compared to a rigid counterpart. In addition, the morphology of the ribbon n a ects its propulsive performance as well, and there could exist an optimal n morphology. To understand how an underactuated undulating n can modify its active and passive n motion to e ectively control the hydrodynamic force and propulsive e ciency. We did a series of experiments using the same robotic n model but with some structural modi cations and we measured n kinematics, net surge force and power consumption. We nd that the under-actuated n can keep the equivalent propulsive e ciency as the fully-actuated counterpart within our experimental parameter range. Moreover, our results demonstrate that the thrust force and power consumption of an under-actuated n follow the same scaling laws as the fully-actuated n. To conduct the free-swimming maneuver study, we developed a self-contained, free-swimming robot propelled by an undulatory n, which is able to perform the following maneuvers: forward, reversed swimming and hovering motion. We also performed V3V PIV experiments to capture the ow structures generated by the robotic device. Our results show that the robot can reach higher swimming e ciency at low frequencies. As the number of traveling waves increases, the robot swims more stably in roll, pitch and yaw motions. For cases with varying wave amplitudes, traveling wave with incremental wave amplitude can achieve free-swimming velocity higher than that of decremental wave amplitude. However, the latter case can generate higher pitch angles. For the robot with slightly negative-pitched pectoral ns, it can perform slow diving maneuvers. These ndings demonstrate that we can take advantage of the undulating ribbon n propulsion to achieve high maneuverability for the future underwater vehicles in complex environment.
Show less
Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004853, http://purl.flvc.org/fau/fd/FA00004853
Subject Headings
Underwater propulsion., Wave-motion, Theory of., Remote submersibles--Design., Marine engineering.
Format
Document (PDF)
Methodology for fault detection and diagnostics in an ocean turbine using vibration analysis and modeling
Title
Methodology for fault detection and diagnostics in an ocean turbine using vibration analysis and modeling.
Creator
Mjit, Mustapha., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This thesis describes a methodology for mechanical fault detection and diagnostics in an ocean turbine using vibration analysis and modeling. This methodology relies on the use of advanced methods for machine vibration analysis and health monitoring. Because of some issues encountered with traditional methods such as Fourier analysis for non stationary rotating machines, the use of more advanced methods such as Time-Frequency Analysis is required. The thesis also includes the development of...
Show moreThis thesis describes a methodology for mechanical fault detection and diagnostics in an ocean turbine using vibration analysis and modeling. This methodology relies on the use of advanced methods for machine vibration analysis and health monitoring. Because of some issues encountered with traditional methods such as Fourier analysis for non stationary rotating machines, the use of more advanced methods such as Time-Frequency Analysis is required. The thesis also includes the development of two LabVIEW models. The first model combines the advanced methods for on-line condition monitoring. The second model performs the modal analysis to find the resonance frequencies of the subsystems of the turbine. The dynamic modeling of the turbine using Finite Element Analysis is used to estimate the baseline of vibration signals in sensors locations under normal operating conditions of the turbine. All this information is necessary to perform the vibration condition monitoring of the turbine.
Show less
Date Issued
2009
PURL
http://purl.flvc.org/FAU/369198
Subject Headings
Marine turbines, Mathematical models, Fluid dynamics, Structural dynamics, Composite materials, Mathematical models, Elastic analysis (Engineering)
Format
Document (PDF)
A Design Concept for Launch and Recovery of REMUS 100 AUV from WAM-V 16 USV
Title
A Design Concept for Launch and Recovery of REMUS 100 AUV from WAM-V 16 USV.
Creator
Palmaccio, Brendan, Dhanak, Manhar, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description
In this thesis, feasibility of a concept for launch and recovery of the Remus AUV from WAM-V USV is investigated. A modular recovery system which can be added to the WAM-V payload tray was designed, and based on a review of previous literature a CONOPS was developed for the launch and recovery process. The first phase of the CONOPS, which pertains to the position of the REMUS initially on the free surface prior to sling engagement is simulated using ANSYS AQWA. Preprocessing for the...
Show moreIn this thesis, feasibility of a concept for launch and recovery of the Remus AUV from WAM-V USV is investigated. A modular recovery system which can be added to the WAM-V payload tray was designed, and based on a review of previous literature a CONOPS was developed for the launch and recovery process. The first phase of the CONOPS, which pertains to the position of the REMUS initially on the free surface prior to sling engagement is simulated using ANSYS AQWA. Preprocessing for the simulation involved simplification of the model in ANSYS SpaceClaim to achieve a proper mesh as well as theoretical calculations of the input parameters for wave environment and point masses etc. The simulation was evaluated by taking into consideration two wave environment scenarios: beam sea’s (-90 degrees) and head seas (0 degrees). The wave environment was based on a linear frequency range for the waves which considered wavelengths that correspond to half and double the length of the WAM-V 16’. The significance of the simulation is characterized through identifying the ideal direction and wave frequency range for recovery based on the RAOs of the two vehicles.
Show less
Date Issued
2023
PURL
http://purl.flvc.org/fau/fd/FA00014216
Subject Headings
Autonomous underwater vehicles--Design and construction, Marine engineering, Littoral combat ships
Format
Document (PDF)
Analysis of ship hull and plate vibrations caused by wave forces
Title
Analysis of ship hull and plate vibrations caused by wave forces.
Creator
Lakitosh, Fnu, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
In the present dissertation, the hydrodynamic and hydro-elastic characteristics of ship hull and plate vibrations are analyzed using theoretical and numerical methods. The wave forces are determined using a suite of methods which include the Froude-Krylov method for incident wave forces, Wagner's method and ABS rules for the slamming wave force, and numerical methods for nonlinear wave radiation forces. Finite difference methods are developed to determine the wave forced vibrations of ship...
Show moreIn the present dissertation, the hydrodynamic and hydro-elastic characteristics of ship hull and plate vibrations are analyzed using theoretical and numerical methods. The wave forces are determined using a suite of methods which include the Froude-Krylov method for incident wave forces, Wagner's method and ABS rules for the slamming wave force, and numerical methods for nonlinear wave radiation forces. Finite difference methods are developed to determine the wave forced vibrations of ship hull plates which are modeled using a range of plate theories including nonlinear plate theory with and without material damping and orthotropic plate theory for stiffened hull plates. For small amplitude deformation of thin plates, a semi-theoretical superposition method is used to determine the free and forced vibrations. The transient ship hull vibration due to whipping is also analyzed using the finite difference method. Results, in the form of deformations and stress distributions, are obtained for a range of scantling and wave parameters to identify key parameters to consider in ship structural design.
Show less
Date Issued
2012
PURL
http://purl.flvc.org/FAU/3342196
Subject Headings
Vibration (Marine engineering), Hulls (Naval architecture), Ships, Hydraulic impact, Ocean waves, Mathematical models, Fluid dynamics, Mathematical models
Format
Document (PDF)
Modeling and simulation on the yard trailers deployment in the maritime container terminal
Title
Modeling and simulation on the yard trailers deployment in the maritime container terminal.
Creator
Zhao, Yueqiong, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
In recent years, there has been an exponential increase in container volume shipment within intermodal transportation systems. Container terminals as part of the global port system represent important hubs within this intermodal transportation system. Thus, the need to improve the operational efficiency is the most important issue for container terminals from an economic standpoint. Moreover, intermodal transportation systems, ports and inland transport facilities should all be integrated...
Show moreIn recent years, there has been an exponential increase in container volume shipment within intermodal transportation systems. Container terminals as part of the global port system represent important hubs within this intermodal transportation system. Thus, the need to improve the operational efficiency is the most important issue for container terminals from an economic standpoint. Moreover, intermodal transportation systems, ports and inland transport facilities should all be integrated into one coordinated plan. More specifically, a method to schedule different types of handling equipment in an integrated way within a container terminal is a popular topic for researchers. However, not many researchers have addresses this topic in relationship to the simulation aspect which will test feasible solutions under real container terminal environment parameters. In order to increase the efficiency of operations, the development of mathematical models and algorithms is critical in finding the best feasible solution. The objective of this study is to evaluate the feasible solution to find the proper number of Yard Trailers (YTs) with the minimal cost for the container terminals. This study uses the Dynamic YTs operation's method as a background for modeling. A mathematical model with various constraints related to the integrated operations among the different types of handling equipment is formulated. This model takes into consideration both serving time of quay cranes and yard cranes, and cost reduction strategies by decreasing use of YTs with the specific objective of minimum total cost including utilization of YTs and vessel berthing. In addition, a heuristic algorithm combined with Monte Carlo Method and Brute-Force Search are employed. The early Stage Technique of Monte Carlo method is proposed to generate vast random numbers to replicate simulation for real cases., The Brute-Force Search is used for identifying all potential cases specific to the conditions of this study. Some preliminary numerical test results suggest that this method is good for use in conjunction with simulation of container terminal operation. The expected outcome of this research is a solution to obtain the proper number of YTs for transporting containers with a minimum cost; thus, improving the operational efficiency in a container terminal.
Show less
Date Issued
2011
PURL
http://purl.flvc.org/FAU/3174315
Subject Headings
Marine terminals, Computer programs, Computer algorithms, Materials management, Warehouses, Management, Transportation engineering, Freight and freightage
Format
Document (PDF)