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Title: BEHAVIOR OF A SWIRLING BUOYANT TURBULENT JET IN A CROSS FLOW.
Creator: VISWANATHAN, SURESH., Florida Atlantic University, Su, Tsung-Chow, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The behavior of a swirling buoyant turbulent jet in a cross flow has been studied. Dimensional analysis has been carried out to obtain asymptotic relations for the jet trajectory and dilution. Experiments were carried out to ascertain the validity of the relations obtained and to evaluate the constants arising in the analysis. While photographic observations were made to study the jet trajectory, concentration measurements were made using a light probe. Measurements of the spreading angle of...
Show moreThe behavior of a swirling buoyant turbulent jet in a cross flow has been studied. Dimensional analysis has been carried out to obtain asymptotic relations for the jet trajectory and dilution. Experiments were carried out to ascertain the validity of the relations obtained and to evaluate the constants arising in the analysis. While photographic observations were made to study the jet trajectory, concentration measurements were made using a light probe. Measurements of the spreading angle of the jet were also made. The study indicated that swirl caused an increase in spreading angle of the jet, and a great improvement in jet dilution.
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Date Issued: 1986
PURL: http://purl.flvc.org/fcla/dt/14317
Subject Headings: Jets, Hydrodynamics
Format: Document (PDF)

$Boundary-integral analysis of nonlinear diffraction forces on a submerged body$

Title: Boundary-integral analysis of nonlinear diffraction forces on a submerged body.
Creator: Vinayan, Vimal., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A three-dimensional nonlinear time-dependent boundary-integral algorithm is developed to compute wave forces on an underwater vehicle. The effect of viscosity is neglected and the cases for which the effects could be important are discussed. The present algorithm is however an efficient tool to determine wave forces on a submerged body and can also be integrated into a viscous flow algorithm. A numerical wave tank is constructed for the simulation. A damping layer is introduced to minimize...
Show moreA three-dimensional nonlinear time-dependent boundary-integral algorithm is developed to compute wave forces on an underwater vehicle. The effect of viscosity is neglected and the cases for which the effects could be important are discussed. The present algorithm is however an efficient tool to determine wave forces on a submerged body and can also be integrated into a viscous flow algorithm. A numerical wave tank is constructed for the simulation. A damping layer is introduced to minimize spurious reflection of scattered waves at the open boundary. A sinusoidal progressive pressure patch is used to generate incident waves. Wave forces are determined using four different methods: viz., (1) Froude-Krylov volume integration method, (2) Froude-Krylov surface pressure integration method, (3) Linear diffraction analysis and (4) Nonlinear diffraction analysis for a range of parameters including incident wavelength and wave height. Results are compared to quantify effects of nonlinearity and diffraction effect of the body.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13048
Subject Headings: Waves--Diffraction, Boundary element methods, Hydrodynamics, Surface waves (Oceanography)
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)

$Computed tomographic measurements of void fraction and modeling of the flow in bubble columns$

Title: Computed tomographic measurements of void fraction and modeling of the flow in bubble columns.
Creator: Kumar, Sailesh B., Florida Atlantic University, Moslemian, Davood, Dudukovic, M. P., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A complete understanding of the gas-liquid two phase flow in bubble columns is required for the development of reliable models for scale-up of these multiphase reactors. Although several models have been proposed to describe the hydrodynamics. lack of adequate experimental data has hindered meaningful evaluation of model parameters and model predictions. The Computer Automated Radioactive Particle Tracking ( CARPT) facility that was implemented earlier has provided interesting results on the...
Show moreA complete understanding of the gas-liquid two phase flow in bubble columns is required for the development of reliable models for scale-up of these multiphase reactors. Although several models have been proposed to describe the hydrodynamics. lack of adequate experimental data has hindered meaningful evaluation of model parameters and model predictions. The Computer Automated Radioactive Particle Tracking ( CARPT) facility that was implemented earlier has provided interesting results on the recirculation patterns of the liquid phase. The technique has provided quantitative information on liquid velocities and turbulence parameters as well. In addition to these hydrodynamic parameters the measurement of void fraction is also important. To complement the capabilities of CARPT a scanner for ;-ray Computed Tomography (CT) was implemented to quantify the local void fraction and its distribution in two phase flow systems. The automated scanner is capable of imaging flows in test sections between 0.02.5 m and 0..15 m in diameter at different elevations above the distributor. The scanner makes use of the same detectors used in the CARPT facility and with the use of a specially designed moving collimator provides a spatial resolution of about 5 mm. A non-conventional algorithm based on maximum likelihood principles called the E-M algorithm was used for imagw reconstruction. Long scanning times are required leading to time averaged density profiles. Although the system is only capable of providing time averaged void fraction distributions. it can provide unique information concerning the structure of two phase flow. The system performance was evaluated by identifying the sources of errors in measurement and their bounds. The capabilities of the scanner for imaging void fraction distribution was demonstrated both qualitatively and quantitatively. Fse of existing radiation detectors and the associated signal processing and data acquisition system helped in reducing the cost of the system. The scanner was utilized to quantify the local void fraction and its distribution in bubble columns of five diameters (0.10. 0.14, 0.19, 0.26. 0.30 m internal diameter) and at four superficial gas velocities. The effect of various operating parameters such as column diameter, superficial gas velocity. the type of distributor. the static liquid height and some changes in the physical properties of the liquid phase were studied. For the first time a comprehensive characterization of the void fraction in an air water bubble column using a non-invasive technique was achieved. The experimental data obtained using CARPT and CT under identical operating conditions was used for developing a methodology for scale-up of bubble columns using a one dimensional model for liquid recirculation. Successful scale-up of liquid hydrodynamics using a one dimensional model requires an adequate closure scheme for the Reynolds shear stress. The existing correlations for the prescription of the eddy viscosity or the mixing length scale are demonstrated to be applicable only for a limited range of conditions. and consequently cannot be used for scale-up predictions. A method for estimating the mixing length scale has been explored and an attempt at unifying a wide range of data available in the literature within the pun·iew of the method has been made. The futility of such an attempt is attributed to the non-reproducibility of the flow in different laboratories and the conasequent lack of data obtained under identical conditions. It is demonstrated, however, that scale-up based on the mixing length distribution is possible when it is obtained from a consistent set of data for liquid velocity and gas void fraction profiles. Using the present method for prescribing the mixing length scale. model predictions for scale-up compare satisfactorily for the data that was obtained as part of this research. The achievement was that the turbulence length scale estimated in one column diameter was successfully used in predicting the liquid velocities in larger diameter columns.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/12384
Subject Headings: Two-phase flow, Hydrodynamics, Bubble chambers, Tomography, Emission
Format: Document (PDF)

Title: Design of an adaptive nonlinear controller for an autonomous underwater vehicle equipped with a vectored thruster.
Creator: Morel, Yannick., Florida Atlantic University, Leonessa, Alexander, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The tasks Autonomous Underwater Vehicles (AUVs) are expected to perform are becoming more and more challenging. Thus, to be able to address such tasks, we implemented a high maneuverability propulsion system: a vectored thruster. The design of a vehicle equipped with such a propulsion system will be presented, from a mechanical, electronic and software point of view. The motion control of the resulting system is fairly complex, and no suitable controller is available in the literature....
Show moreThe tasks Autonomous Underwater Vehicles (AUVs) are expected to perform are becoming more and more challenging. Thus, to be able to address such tasks, we implemented a high maneuverability propulsion system: a vectored thruster. The design of a vehicle equipped with such a propulsion system will be presented, from a mechanical, electronic and software point of view. The motion control of the resulting system is fairly complex, and no suitable controller is available in the literature. Accordingly, we will present the derivation of a novel tracking controller, whose adaptive properties will compensate for the lack of knowledge of the system's parameters. Computer simulations are provided and show the performance and robustness of the proposed control algorithm to external perturbations, unmodelled dynamics and dynamics variation. We finally illustrate the advantage of using an adaptive controller by comparing the presented controller to a Proportional Integral Derivative controller.
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Date Issued: 2002
PURL: http://purl.flvc.org/fcla/dt/12986
Subject Headings: Hydrodynamics, Nonlinear control theory, Adaptive control systems, Oceanographic submersibles
Format: Document (PDF)

Title: Dynamic simulation and control of an autonomous surface vehicle.
Creator: VanZwieten, Tannen S., Florida Atlantic University, Leonessa, Alexander, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Autonomous Surface Vehicle (ASV) research and development is inspired by the navigating and communicatiog challenges of Autonomous Underwater Vehicles (AUVs). The development objective is to provide real time positioning of and communication with AUVs through the air-sea interface. Despite extensive research on AUVs, the ASV has had limited research. The NAVY's desire to make AUV's defense capabilities realizable adds to the project's appeal. Guidance and control play an integral part in the...
Show moreAutonomous Surface Vehicle (ASV) research and development is inspired by the navigating and communicatiog challenges of Autonomous Underwater Vehicles (AUVs). The development objective is to provide real time positioning of and communication with AUVs through the air-sea interface. Despite extensive research on AUVs, the ASV has had limited research. The NAVY's desire to make AUV's defense capabilities realizable adds to the project's appeal. Guidance and control play an integral part in the ASV's success, motivating this thesis work. The overall vehicle dynamics were modeled and numerically simulated for 3 DOF lateral motion. These are development tools for the testing and tuning of PID and adaptive control algorithms. The results show the adaptive controller to be advantageous in terms of tuning, robustness and tracking performances. It uses a single layer neural network that bypasses the need for information about the system's dynamic structure and characteristics and provides portability.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13081
Subject Headings: Hydrodynamics, Adaptive control systems--Computer simulation, PID controllers--Computer simulation, Neural networks (Computer science)
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: AN EXPERIMENTAL STUDY OF BIOFOULING ON A FLAT PLATE SUSPENDED IN A UNIFORM FLOW.
Creator: WOOD, MARK ALAN., Florida Atlantic University, Tennant, Jeffrey S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: An investigation was conducted to determine the relationship between hydrodynamic boundary layer parameters and biofouling growth rates. A summary of previous investigations of hydrodynamic effects on biofouling is presented. Wall shear stress is shown to be an important parameter and is described in detail. A submersible water tunnel was designed to allow investigation of a flat plate subject to a uniform flow of seawater. Parallel flow past a flat plate with a laminar boundary layer was...
Show moreAn investigation was conducted to determine the relationship between hydrodynamic boundary layer parameters and biofouling growth rates. A summary of previous investigations of hydrodynamic effects on biofouling is presented. Wall shear stress is shown to be an important parameter and is described in detail. A submersible water tunnel was designed to allow investigation of a flat plate subject to a uniform flow of seawater. Parallel flow past a flat plate with a laminar boundary layer was used to ensure that experimental conditions existed in which a known wall shear stress distribution was establised. Tests were conducted off Virginia Key in Miami, Florida. The results of the experiments clearly indicate the existance of a threshold value of shear stress which inhibits the attachment of the macrofouler under study, the acorn barnacle (Balanus spp.). Reported growth rates from other investigations are presented to substantiate results. Recommendations are made for additional hydrodynamic investigations in dealing with biofouling.
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Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13849
Subject Headings: Fouling, Hydrodynamics
Format: Document (PDF)

Title: Experimental study of flow over a bundle of cylinders.
Creator: Khuc, Hiep Hieu., Florida Atlantic University, Su, Tsung-Chow, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The drag reduction by vortex fusion was investigated. A comparison of flow over a bundle of cylinders in uniform and in disturbed currents was performed in a water channel. The model was subjected to cross flow. A thin cylindrical wire located nearby upstream and leveled at half the height of the test model was used as a source of disturbance. A hydrogen bubble technique was utilized to observe the flow pattern. The accumulation of vortices at stagnating regions in front of a bundle of...
Show moreThe drag reduction by vortex fusion was investigated. A comparison of flow over a bundle of cylinders in uniform and in disturbed currents was performed in a water channel. The model was subjected to cross flow. A thin cylindrical wire located nearby upstream and leveled at half the height of the test model was used as a source of disturbance. A hydrogen bubble technique was utilized to observe the flow pattern. The accumulation of vortices at stagnating regions in front of a bundle of cylinders transformed into a counter-rotated curl at leading edges of each leading cylinder in the bundle. Measurements were carried out by a computerized data acquisition system. Drag coefficient measurements, digital spectral and fourier analyses were also performed. Results have shown that a drag reduction can be obtained by introducing a thin cylindrical wire in front of the stagnation.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/15026
Subject Headings: Vortex-motion, Fluid dynamics, Cylinders, Fourier transformations, Hydrodynamics
Format: Document (PDF)

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: Hydrodynamic analysis of an underwater body including free-surface effects.
Creator: Puaut, Christophe., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Boundary integral algorithms are developed to analyze three-dimensional inviscid fluid-body interactions, including the nonlinear free-surface effects. Hydrodynamic coefficients are computed for various body geometries, some corresponding to that of small underwater vehicles, in deep waters and near the free surface. The fully nonlinear unsteady wave-radiation problem corresponding to forced submerged-body oscillations and forward translation are solved using the mixed Eulerian-Lagrangian...
Show moreBoundary integral algorithms are developed to analyze three-dimensional inviscid fluid-body interactions, including the nonlinear free-surface effects. Hydrodynamic coefficients are computed for various body geometries, some corresponding to that of small underwater vehicles, in deep waters and near the free surface. The fully nonlinear unsteady wave-radiation problem corresponding to forced submerged-body oscillations and forward translation are solved using the mixed Eulerian-Lagrangian formulation (Longuet-Higgins and Cokelet, 1976). By implementing the leading-order free-surface conditions on the calm surface, linear time-domain solutions are also obtained. The nonlinear and linear results are compared to quantify the nonlinear free-surface effects. Linear frequency-domain analysis of the wave-body interactions is also carried out using a boundary-integral method based on the simple-source distribution (Yeung, 1974). The linear time-domain and the latter frequency-domain results are also compared for a validation of the algorithms.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/12845
Subject Headings: Boundary element methods, Oceanographic submersibles, Hydrodynamics
Format: Document (PDF)

Title: Hydrodynamic Interactions of Pitching Hydrofoils in Close Formation.
Creator: Boltri, Michael A., Curet, Oscar M., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Hydrodynamics interaction is a factor in the performance of fish schooling or underwater vessels in close formation. In this work, we visualized the wake structure of pitching hydrofoils using an inclined soap film. We considered one-, two-, three- and nine-foil configurations with different spacing and actuation parameters: amplitude (A), frequency (f), phase difference (), and flow speed (U). The wake structures were recorded with a high-speed camera and analyzed to measure the vortex...
Show moreHydrodynamics interaction is a factor in the performance of fish schooling or underwater vessels in close formation. In this work, we visualized the wake structure of pitching hydrofoils using an inclined soap film. We considered one-, two-, three- and nine-foil configurations with different spacing and actuation parameters: amplitude (A), frequency (f), phase difference (), and flow speed (U). The wake structures were recorded with a high-speed camera and analyzed to measure the vortex angle created. The wake structure of two- and three-foil configurations were compared with the Strouhal number, St = fA/U, of a single foil. For the nine-foil configuration, the wake velocity and the standard deviation of the velocity were used to interpret the hydrodynamic interaction. It was found that both spacing and phase difference between foils are relevant in the hydrodynamic interaction. Qualitative observations are also made, and vortex street behavior characteristics are identified.
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Date Issued: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013627
Subject Headings: Hydrodynamics, Hydrofoils
Format: Document (PDF)

Title: HYDRODYNAMIC PERFORMANCE AND SEAKEEPING ANALYSIS OF A CATAMARAN IN TRANSFORMING NEAR-SHORE HEAD AND FOLLOWING SEAS.
Creator: Ulgen, Kayhan, Dhanak, Manhar R., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: A computational investigation of the hydrodynamic and seakeeping performance of a catamaran in calm, and in the presence of transforming head and following seas in waters of constant and varying depths is described. Parametric studies were conducted for a selected WAM-V 16 catamaran geometry using OpenFOAM® to uncover the physical phenomena. In the process a methodology has been developed for simulating the interactions between the vehicle and the shallow water environment akin to that in the...
Show moreA computational investigation of the hydrodynamic and seakeeping performance of a catamaran in calm, and in the presence of transforming head and following seas in waters of constant and varying depths is described. Parametric studies were conducted for a selected WAM-V 16 catamaran geometry using OpenFOAM® to uncover the physical phenomena. In the process a methodology has been developed for simulating the interactions between the vehicle and the shallow water environment akin to that in the coastal environment. The multiphase flow around the catamaran, including the six degrees-of-freedom motion of the vehicle, was modeled using a Volume of Fluid (VoF) method and solved using a dynamic mesh. The numerical approach was validated through computing benchmark cases and comparing the results with previous work. It is found that in a calm shallow water environment the total resistance, dynamic trim and sinkage of a catamaran in motion can be significantly impacted by the local water depth. The variations of the impact with depth and length-based Froude numbers are characterized. The impact varies as the vehicle moves from shallow waters to deep water or vice versa. In the presence of head and following small-amplitude seas, interesting interactions between incident waves and those generated by the vehicle are observed and are characterized for their variation with Froude number and water depth.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013942
Subject Headings: Seakeeping, Catamarans, Hydrodynamics, Computational fluid dynamics
Format: Document (PDF)

Title: Hydrodynamics and control of an autonomous underwater vehicle equipped with a vectored thruster.
Creator: Le Page, Yann Georges., Florida Atlantic University, Holappa, Kenneth W., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In this study, a laminar flow hull shape is implemented on an Autonomous Underwater Vehicle (AUV), with boundary layer suction at the aft end of the hull to prevent separation. The hull shape has the largest diameter of the vehicle near the aft end of the hull resulting in an accelerating flow over the majority of the hull's surface. The problem of axially symmetrical flow around the AUV is solved using a potential flow analysis. A finite difference algorithm evaluates the stream function,...
Show moreIn this study, a laminar flow hull shape is implemented on an Autonomous Underwater Vehicle (AUV), with boundary layer suction at the aft end of the hull to prevent separation. The hull shape has the largest diameter of the vehicle near the aft end of the hull resulting in an accelerating flow over the majority of the hull's surface. The problem of axially symmetrical flow around the AUV is solved using a potential flow analysis. A finite difference algorithm evaluates the stream function, leading to the computation of fluid velocity and pressure fields. The boundary layer characteristics are analyzed to predict the risk of separation. The numerical results are compared with laboratory measurements of the flow using a Particle Image Velocimetry system. Fuzzy Logic Sliding Mode Controllers are implemented to control the vectored thruster vehicle, and are simulated using a six-degree of freedom dynamic model of the vehicle.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/15766
Subject Headings: Boundary layer, Laminar flow, Hydrodynamics, Oceanographic submersibles--Mathematical models
Format: Document (PDF)

Title: NOISE PREDICTION METHODS.
Creator: Perry, Nicole Kent, Glegg, Stewart, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Noise prediction methods are necessary in aspects of aerodynamic and hydrodynamic engineering. Predictive models of noise from rotating machinery ingesting turbulence is of much interest and relatively recently studied. This thesis presents a numerical method processed in a series of three codes that was written and edited to receive input for geometrical features of rotating machinery, as well as, adjustments to turbulent operating conditions. One objective of this thesis was to create a...
Show moreNoise prediction methods are necessary in aspects of aerodynamic and hydrodynamic engineering. Predictive models of noise from rotating machinery ingesting turbulence is of much interest and relatively recently studied. This thesis presents a numerical method processed in a series of three codes that was written and edited to receive input for geometrical features of rotating machinery, as well as, adjustments to turbulent operating conditions. One objective of this thesis was to create a platform of analysis for any rotor design to obtain five parameters necessary for noise prediction; 1) the hydrodynamic inflow angle to each blade section, 2) chord length as a function of radius, 3) the cylindrical radius of each blade section, 4) & 5) the leading edge as a function of span in both the rotor-plane and as a function of axial distance downstream. Another objective of this thesis was to use computational fluid dynamics (CFD), specifically by using a Reynold’s-Averaged Navier-Stokes (RANS) Shear Stress Transport (SST) 𝑘 − 𝜔 model simulation in ANSYS Fluent, to obtain the turbulent kinetic energy distribution, also necessary in the noise prediction method presented. The purpose of collecting the rotor geometry data and turbulent kinetic energy data was to input the values into the first of the series of codes and run the calculation so that the output spectra could be compared to experimental noise measurements conducted at the Stability Wind Tunnel at Virginia Tech. The comparison shows that the prediction method results in data that can be reliable if careful attention is payed to the input parameters and the length scale used for analysis. The significance of this research is the noise prediction method presented and used simplifies the model of turbulence by using a correlation function that can be determined by a one-dimensional function while also simplifying the iterations completed on rotor blade to calculate the unsteady forces.
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Date Issued: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013487
Subject Headings: Noise, Aerodynamic noise, Hydrodynamics, Noise control--Mathematical models
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: 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)

Ships (4)	+ -
Oceanographic submersibles (3)	+ -
Boundary element methods (2)	+ -
Fluid dynamics (2)	+ -
Ship propulsion (2)	+ -

Adaptive control systems (1)	+ -
Adaptive control systems--Computer simulation (1)	+ -
Aerodynamic noise (1)	+ -
Boundary layer (1)	+ -
Bubble chambers (1)	+ -
Catamarans (1)	+ -
Computational fluid dynamics (1)	+ -
Cylinders (1)	+ -
Electric motors, Induction (1)	+ -
Electric propulsion (1)	+ -
Field orientation principle (Electric engineering) (1)	+ -
Fouling (1)	+ -
Fourier transformations (1)	+ -
Hydrofoils (1)	+ -
Jets (1)	+ -
Laminar flow (1)	+ -
Naval architecture (1)	+ -
Neural networks (Computer science) (1)	+ -
Noise (1)	+ -
Noise control--Mathematical models (1)	+ -
Nonlinear control theory (1)	+ -
Oceanographic submersibles--Mathematical models (1)	+ -
PID controllers--Computer simulation (1)	+ -
Propellers (1)	+ -

College of Engineering and Computer Science (17)	+ -
Florida Atlantic University (13)	+ -
Ananthakrishnan, Palaniswamy (3)	+ -
Leonessa, Alexander (2)	+ -
Su, Tsung-Chow (2)	+ -

Altamirano, Luis. (1)	+ -
Boltri, Michael A. (1)	+ -
Curet, Oscar M. (1)	+ -
Dhanak, Manhar R. (1)	+ -
Dudukovic, M. P. (1)	+ -
Glegg, Stewart (1)	+ -
Holappa, Kenneth W. (1)	+ -
Khuc, Hiep Hieu. (1)	+ -
Kindel, Michael. (1)	+ -
Kumar, Sailesh B. (1)	+ -
Le Page, Yann Georges. (1)	+ -
Lorio, Justin M. (1)	+ -
Morel, Yannick. (1)	+ -
Moslemian, Davood (1)	+ -
Perry, Nicole Kent (1)	+ -
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