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Title: Flow visualization of the ventilated cavities generated by a surface piercing propeller.
Creator: Altamirano, Luis., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In the present study, 3 wake parameters are semi-automatically measured in 63 composite-labeled images of a surface piercing propeller tested at yaw angles 0-30 degrees, pitch angles 0-15 degrees, propeller immersion ratios of 0.33 and 0.50 and scaled advance ratios 0.656-1.927. A fourth wake parameter is measured in four composite labeled images of yaw angles 0-30 degrees, pitch angle 0 degrees, immersion ratios of 0.33 and 0.50 and scaled advance ratios 1.363-1.927. Measurements are plotted...
Show moreIn the present study, 3 wake parameters are semi-automatically measured in 63 composite-labeled images of a surface piercing propeller tested at yaw angles 0-30 degrees, pitch angles 0-15 degrees, propeller immersion ratios of 0.33 and 0.50 and scaled advance ratios 0.656-1.927. A fourth wake parameter is measured in four composite labeled images of yaw angles 0-30 degrees, pitch angle 0 degrees, immersion ratios of 0.33 and 0.50 and scaled advance ratios 1.363-1.927. Measurements are plotted against propeller's angular position. Major findings include the behavior of wake parameters as the values of scaled advance ratio, yaw angle, pitch angle, and immersion ratio vary.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1927299
Subject Headings: Ships, Hydrodynamics, Ship propulsion
Format: Document (PDF)

Title: Open water testing of a surface piercing propeller with varying submergence, yaw angle and inclination angle.
Creator: Lorio, Justin M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The use of surface piercing propellers (SPPs) shows promise for high speed operation by virtually eliminating appendage drag, which can be as much as 30 percent of the total drag on a vehicle at high speeds. The scarcity of available systematic test data has made reliable performance prediction difficult. The primary objective of this research is to obtain experimental performance prediction data that can be used in SPP design. In a series of open water tests in a non-pressurized towing tank...
Show moreThe use of surface piercing propellers (SPPs) shows promise for high speed operation by virtually eliminating appendage drag, which can be as much as 30 percent of the total drag on a vehicle at high speeds. The scarcity of available systematic test data has made reliable performance prediction difficult. The primary objective of this research is to obtain experimental performance prediction data that can be used in SPP design. In a series of open water tests in a non-pressurized towing tank facility, force transducer measurements were taken at tip immersion ratios from 0.5 to .33, yaw angles from 0° to 30° and inclination angles from 0° to 15° over a range of advance ratios from 0.8 to 1.8. Force transducer measurements were taken for thrust, torque, side forces and moments. These results will help develop a baseline for the verification of SPP performance prediction.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1930498
Subject Headings: Ships, Hydrodynamics, Ship propulsion, Propellers
Format: Document (PDF)

Title: ANALYSIS OF HYDRODYNAMIC INTERACTIONS BETWEEN SHIPS IN CONFINED WATERS.
Creator: Ananthakrishnan, Palaniswamy, Florida Atlantic University, Lin, Newman K.
Abstract/Description: The hydrodynamic interactions between ships in confined waters, restricted in width and depth, is analysed using a numerical surface singularity method called the Panel method. Based on potential flow and rigid free surface assumptions, a source distribution is utilized over the boundary surfaces to model the flow. The strength of the source distribution is obtained on satisfying the normal kinematic boundary conditions, i.e. as a solution of an integral equation. Discretization of the...
Show moreThe hydrodynamic interactions between ships in confined waters, restricted in width and depth, is analysed using a numerical surface singularity method called the Panel method. Based on potential flow and rigid free surface assumptions, a source distribution is utilized over the boundary surfaces to model the flow. The strength of the source distribution is obtained on satisfying the normal kinematic boundary conditions, i.e. as a solution of an integral equation. Discretization of the boundary surfaces yields a system of linear algebraic equations corresponding to the boundary integral equation, which then is solved numerically. From the singularity distribution, the velocity components, pressure coefficients and finally the interaction loads are calculated.
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Date Issued: 1985
PURL: http://purl.flvc.org/fcla/dt/14272
Subject Headings: Ships--Hydrodynamics
Format: Document (PDF)

Title: MATHEMATICAL MODELING OF CRAFT DRIFT IN AN OCEAN ENVIRONMENT.
Creator: KANG, SIN YOUNG., Florida Atlantic University, Su, Tsung-Chow, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A mathematical model, which accounts for the essential effects of environmental loads and vehicle characteristics from a fluid dynamics point of view, is developed to forecast the position of a craft drifting on the sea surface. The study is intended to provide a better understanding of the dynamics of drift and thus to provide a reliable model of drift prediction for use in future search and rescue mission. In the mathematical formulation, three degrees of freedom (surge, sway and yaw) of a...
Show moreA mathematical model, which accounts for the essential effects of environmental loads and vehicle characteristics from a fluid dynamics point of view, is developed to forecast the position of a craft drifting on the sea surface. The study is intended to provide a better understanding of the dynamics of drift and thus to provide a reliable model of drift prediction for use in future search and rescue mission. In the mathematical formulation, three degrees of freedom (surge, sway and yaw) of a craft are analyzed, since they play the most significant role in the drift prediction problem. The governing equations of motions are derived from Newton's law of dynamics and the environmental loads considered are the forces and moments exerted by wind, current and waves. The forces are analyzed in terms of drag, lift, and inertial forces. The moments are obtained by summing the contribution from the above forces. For the computation of the wind loads, the wind gradient as well as craft geometry is accounted for. In the current loads, profile, friction and propeller drags are included. The wave forces are computed by the use of wave spectral density. The formulation includes the effects of craft rotation as well as craft translation. A computer algorithm for the mathematical model is implemented to obtain the numerical result in the time domain. The model is verified by comparing its result with field measurements. For this purpose, a field test was carried out. The agreement between the computed and field measured drift path was excellent. The real time prediction capability of the model was ascertained.
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Date Issued: 1987
PURL: http://purl.flvc.org/fcla/dt/11894
Subject Headings: Ships--Hydrodynamics--Mathematical models, Ocean waves
Format: Document (PDF)

Title: A direct thrust measurement system for a waterjet propelled, free running USV.
Creator: Grimes, John A., von Ellenrieder, Karl, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The relationship between cross-flow at a waterjet inlet and delivered thrust is not fully understood. A direct thrust measurement system was designed for a waterjet propelled, free running USV. To induce sway velocity at the waterjet inlet, which was considered equivalent to the cross flow, circles of varying radii were performed at Reynolds Numbers between 3.48 x 106 and 8.7 x 106 and radii from 2.7 to 6.3 boat lengths. Sway velocities were less than twenty percent of mean forward speed with...
Show moreThe relationship between cross-flow at a waterjet inlet and delivered thrust is not fully understood. A direct thrust measurement system was designed for a waterjet propelled, free running USV. To induce sway velocity at the waterjet inlet, which was considered equivalent to the cross flow, circles of varying radii were performed at Reynolds Numbers between 3.48 x 106 and 8.7 x 106 and radii from 2.7 to 6.3 boat lengths. Sway velocities were less than twenty percent of mean forward speed with slip angles that were less than 20°. Thrust Loading Coefficients were compared to sway as a percent of forward speed. In small radius turns, no relationship was seen, while in larger radius turns, peaks of sway velocity corresponded with drops in thrust, but this was determined to be caused by reduced vehicle yaw in these intervals . Decoupling of thrust and yaw rate is recommended for future research.
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Date Issued: 2013
PURL: http://purl.flvc.org/fau/fd/FA0004023
Subject Headings: Oceanographic instruments -- Evaluation, Propellers, Ship propulsion, Ships -- Hydrodynamics, Stability of ships
Format: Document (PDF)

Title: Determination of Hydrodynamic Coefficients of Multi-Hull Ships for Seakeeping Analysis.
Creator: Chafin, Jesse Ryan, Ananthakrishnan, Palaniswamy, Florida Atlantic University
Abstract/Description: Linear and non-linear hydrodynamic coefficients of single and multiple hulls are obtained using the boundary-integral method. For linear frequency-domain analysis, the boundary-integral method based on a simple source distribution (Yeung [50] was used. The nonlinear time domain simulations were carried out using a boundary-integral algorithm based on the mixed Eulerian-Lagrangian (MEL) formulation (Longuet-Higgins and Cokelet (19] ). Also, linear time domain simulations were carried out by...
Show moreLinear and non-linear hydrodynamic coefficients of single and multiple hulls are obtained using the boundary-integral method. For linear frequency-domain analysis, the boundary-integral method based on a simple source distribution (Yeung [50] was used. The nonlinear time domain simulations were carried out using a boundary-integral algorithm based on the mixed Eulerian-Lagrangian (MEL) formulation (Longuet-Higgins and Cokelet (19] ). Also, linear time domain simulations were carried out by utilizing a simplified mixed Eulerian-Lagrangian formulation and the steady-state results compared with that obtained from linear-frequency domain analysis. Both 2D and 3D results were obtained for a range of parameters such as beam/draft, hull-separation/beam ratios and frequency and amplitude of hull motions. The results shed light on complex wave-body interactions involved in multi-hull ships and identifY critical hydrodynamic and geometric parameters affecting their sea keeping performance. The computational tools developed and the findings thus contribute to design of multi-hull ships for improved atsea performance.
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Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00012511
Subject Headings: Ships--Seakeeping--Mathematical models, Stability of ships, Ships--Hydrodynamics
Format: Document (PDF)

Title: Seakeeping response of a Surface Effect Ship in near-shore transforming seas.
Creator: Kindel, Michael., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Scale model tests are conducted of a Surface Effect Ship in a near-shore developing sea. A beach is built and installed in a wave tank, and a wavemaker is built and installed in the same wave tank. This arrangement is used to simulate developing sea conditions and a 1:30 scale model SES is used for a series of experiments. Pitch and heave measurements are used to investigate the seakeaping response of the vessel in developing seas. The air-cushion pressure and the vessel speed are varied, and...
Show moreScale model tests are conducted of a Surface Effect Ship in a near-shore developing sea. A beach is built and installed in a wave tank, and a wavemaker is built and installed in the same wave tank. This arrangement is used to simulate developing sea conditions and a 1:30 scale model SES is used for a series of experiments. Pitch and heave measurements are used to investigate the seakeaping response of the vessel in developing seas. The air-cushion pressure and the vessel speed are varied, and the seakeeping results are compared as functions of these two parameters. The experiment results show a distinct correlation between the air-cushion pressure and the response amplitude of both pitch and heave. The results of these experiments are compared against results of a computer model of a Surface Effect Ship (SES).
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3355563
Subject Headings: Naval architecture, Fluid dynamics, Wave motion, Theory of, Ships, Hydrodynamics
Format: Document (PDF)

Title: Investigation of marine waterjet inlets during turning maneuvers.
Creator: Duerr, Phillip S., von Ellenrieder, Karl, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Numerical simulations of waterjet inlets have been conducted in order to understand inlet performance during ship turning maneuvers. During turning maneuvers waterjet systems may experience low efficiency, cavitation, vibration, and noise. This study found that during turns less energy arrived at the waterjet pump relative to operating straight ahead, and that the flow field at the entrance of the waterjet pump exhibited a region of both low pressure and low axial velocity. The primary reason...
Show moreNumerical simulations of waterjet inlets have been conducted in order to understand inlet performance during ship turning maneuvers. During turning maneuvers waterjet systems may experience low efficiency, cavitation, vibration, and noise. This study found that during turns less energy arrived at the waterjet pump relative to operating straight ahead, and that the flow field at the entrance of the waterjet pump exhibited a region of both low pressure and low axial velocity. The primary reason for the change in pump inflow uniformity is due to a streamwise vortex. In oblique inflow the hull boundary layer separates when entering the inlet and wraps up forming the streamwise vortex. These changes in pump inflow during turning maneuvers will result in increased unsteady loading of the pump rotor and early onset of pump rotor cavitation.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004364, http://purl.flvc.org/fau/fd/FA00004364
Subject Headings: Fluid dynamics, Ships--Hydrodynamics, Ships--Maneuverability--Simulation methods, Ship handling--Simulation methods, Ship propulsion, Stability of ships, Oceanographic instruments--Evaluation
Format: Document (PDF)

Title: Electric motor control system with application to marine propulsion.
Creator: Roa, Camilo Carlos, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis analyses the behavior of an induction motor based on a mathematical model created for its simulation. The model describes the interaction of its several non linear differential equations to present a simulated output of induced torque and mechanical speed. Considering the applications to marine propulsion, it is also the goal of the project to design and test a control system for the speed of the motor by maintaining a specific cruse speed regardless the perturbations.
Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2705080
Subject Headings: Electric motors, Induction, Electric propulsion, Field orientation principle (Electric engineering), Ships, Hydrodynamics
Format: Document (PDF)

Title: Modeling and control of a vertically tethered marine platform using an active heave compensation system.
Creator: Eide, Linn., Florida Atlantic University, Driscoll, Frederick R.
Abstract/Description: Technology movement toward deeper waters necessitates the control of vertically tethered systems that are used for installing, repairing, and maintaining underwater equipment. This has become an essential ingredient for the future success of the oil industry as the near-shore oil reservoirs are nearly depleted. Increased operation depths cause large oscillations and snap loadings in these longer cables. Research on this topic has been limited, and includes only top feedback control. The...
Show moreTechnology movement toward deeper waters necessitates the control of vertically tethered systems that are used for installing, repairing, and maintaining underwater equipment. This has become an essential ingredient for the future success of the oil industry as the near-shore oil reservoirs are nearly depleted. Increased operation depths cause large oscillations and snap loadings in these longer cables. Research on this topic has been limited, and includes only top feedback control. The controllers developed in this thesis utilize top, bottom and combined top and bottom feedback. They are implemented on a discrete finite element lumped mass cable model. Comparison between PID, LQG and H infinity for all feedback combinations reveal that the Hinfinity controller with both top and bottom feedback has the best performance, while LQG has a more consistent and reliable performance for all feedback cases.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13079
Subject Headings: Cables, Submarine--Mathematical models, Offshore structures--Dynamics, Feedback control systems, Ships--Hydrodynamics
Format: Document (PDF)

Hydrodynamics (4)	+ -
Ship propulsion (4)	+ -
Ships (4)	+ -
Ships--Hydrodynamics (4)	+ -
Stability of ships (3)	+ -

Fluid dynamics (2)	+ -
Propellers (2)	+ -
Cables, Submarine--Mathematical models (1)	+ -
Electric motors, Induction (1)	+ -
Electric propulsion (1)	+ -
Feedback control systems (1)	+ -
Field orientation principle (Electric engineering) (1)	+ -
Naval architecture (1)	+ -
Ocean waves (1)	+ -
Oceanographic instruments -- Evaluation (1)	+ -
Oceanographic instruments--Evaluation (1)	+ -
Offshore structures--Dynamics (1)	+ -
Ship handling--Simulation methods (1)	+ -
Ships -- Hydrodynamics (1)	+ -
Ships--Hydrodynamics--Mathematical models (1)	+ -
Ships--Maneuverability--Simulation methods (1)	+ -
Ships--Seakeeping--Mathematical models (1)	+ -
Wave motion, Theory of (1)	+ -

College of Engineering and Computer Science (7)	+ -
Department of Ocean and Mechanical Engineering (7)	+ -
Florida Atlantic University (5)	+ -
Ananthakrishnan, Palaniswamy (2)	+ -
von Ellenrieder, Karl (2)	+ -

Altamirano, Luis. (1)	+ -
Chafin, Jesse Ryan (1)	+ -
Driscoll, Frederick R. (1)	+ -
Duerr, Phillip S. (1)	+ -
Eide, Linn. (1)	+ -
Grimes, John A. (1)	+ -
KANG, SIN YOUNG. (1)	+ -
Kindel, Michael. (1)	+ -
Lin, Newman K. (1)	+ -
Lorio, Justin M. (1)	+ -
Roa, Camilo Carlos (1)	+ -
Su, Tsung-Chow (1)	+ -

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