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- Title
- Dissipation and eddy mixing associated with flow past an underwater turbine.
- Creator
- Reza, Zaqie, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objective of this thesis is to analyze the flow past an ocean current turbine using a finite volume Navier-Stokes CFD solver. A full 3-D RANS approach in a moving reference frame is used to model the flow. By employing periodic boundary conditions, one-third of the flow-field is analyzed and the output is replicated to other sectors. Following validation of the computation with an experimental study, the flow fields and particle paths for the case of uniform and sheared incoming flows...
Show moreThe objective of this thesis is to analyze the flow past an ocean current turbine using a finite volume Navier-Stokes CFD solver. A full 3-D RANS approach in a moving reference frame is used to model the flow. By employing periodic boundary conditions, one-third of the flow-field is analyzed and the output is replicated to other sectors. Following validation of the computation with an experimental study, the flow fields and particle paths for the case of uniform and sheared incoming flows past a generic turbine with various blade pitch angles are evaluated and analyzed. Flow field and wake expansion are visualized. Eddy viscosity effects and its dependence on flow field conditions are investigated.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2683537
- Subject Headings
- Vibration (Aerodynamics), Fine element method, Marine turbines, Mathematical models, Water currents, Forecasting, Computational fluid dynamics
- 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.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1927299
- Subject Headings
- Ships, Hydrodynamics, Ship propulsion
- 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
- Enhancement of spike and stab resistance of flexible armor using nanoparticles and a cross-linking fixative.
- Creator
- Lambert, Vincent., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A novel approach has been introduced in making flexible armor composites. Armor composites are usually made by reinforcing Kevlar fabric into the mixture of a polymer and nanoscale particles. The current procedure deviates from the traditional shear thickening fluid (STF) route and instead uses silane (amino-propyl-trimethoxy silane) as the base polymer. In addition, a cross-linking fixative such as Glutaraldehyde (Gluta) is added to the polymer to create bridges between distant pairs of...
Show moreA novel approach has been introduced in making flexible armor composites. Armor composites are usually made by reinforcing Kevlar fabric into the mixture of a polymer and nanoscale particles. The current procedure deviates from the traditional shear thickening fluid (STF) route and instead uses silane (amino-propyl-trimethoxy silane) as the base polymer. In addition, a cross-linking fixative such as Glutaraldehyde (Gluta) is added to the polymer to create bridges between distant pairs of amine groups present in Kevlar and silated nanoparticles. Water, silane, nanoparticles and Gluta are mixed using a homogenizer and an ultra-sonochemical technique. Subsequently, the admixture is impregnated with Kevlar - bypassing the heating and evaporating processes involved with STF. The resulting composites have shown remarkable improvement in spike resistance; at least one order higher than that of STF/Kevlar composites. The source of improvement has been traced to the formation of secondary amine C-N stretch due to the presence of Gluta.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186769
- Subject Headings
- Armor, Design and construction, Composite materials, Testing, Nanoparticles, Testing, Viscoelasticity
- Format
- Document (PDF)
- Title
- Effects of bio-diesel fuel blends on the performance and emissions of diesel engine.
- Creator
- Bastiani, Sergio., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This study presents an experimental investigation into the effects of running biodiesel fuel blends on conventional diesel engines. Bio fuels provide a way to produce fuels without redesigning any of the engine technology present today, yet allowing for green house emissions to decrease. Bio-diesel is one of these types of emerging bio-fuels, which has an immediate alternative fuel aspect to it, while providing a decrease in green house emissions, as well as a solution to recycling used Waste...
Show moreThis study presents an experimental investigation into the effects of running biodiesel fuel blends on conventional diesel engines. Bio fuels provide a way to produce fuels without redesigning any of the engine technology present today, yet allowing for green house emissions to decrease. Bio-diesel is one of these types of emerging bio-fuels, which has an immediate alternative fuel aspect to it, while providing a decrease in green house emissions, as well as a solution to recycling used Waste Vegetable Oils which are other wise disposed. This study shows how by blending bio-diesel with petroleum diesel at intervals of B5, B10, B15, and B20 decrease green house emissions can significantly while maintaining similar performance output and efficiency with respect to 100% petroleum diesel.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166446
- Subject Headings
- Biodiesel fuels, Research, Biodiesel fuels, Environmental aspects, Diesel motor, Alternative fuels, Testing, Greenhouse effect, Atmospheric
- Format
- Document (PDF)
- Title
- Fire performance of high strength concrete materials and structural concrete.
- Creator
- Liu, Lixian., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In recent years, high strength concrete (HSC) is becoming an attractive alternative to traditional normal strength concrete (NSC), and is used in a wide range of applications. With the increased use of HSC, concern has developed regarding the behavior of such concrete in fire. Until now, the fire performance of HSC is not fully understood and more research is needed. Full-scale fire testing is time consuming and expensive, and the real fire scenario is different from the standard fire....
Show moreIn recent years, high strength concrete (HSC) is becoming an attractive alternative to traditional normal strength concrete (NSC), and is used in a wide range of applications. With the increased use of HSC, concern has developed regarding the behavior of such concrete in fire. Until now, the fire performance of HSC is not fully understood and more research is needed. Full-scale fire testing is time consuming and expensive, and the real fire scenario is different from the standard fire. Performance-based assessment methods, including numerical analysis and simplified method, are being accepted in an increasing number of countries. In this dissertation, the fire testing results both of HSC and NSC are presented, performance-based numerical models are developed to study the fire performance of reinforced concrete (RC) members, and simplified calculation methods are proposed to estimate the load capacity of fire-damaged RC columns/beams. A detailed and comprehensive literature review is presented that provides background information on the high temperature behavior of concrete materials and RC members, as well as information on fire performance assessment procedures and objectives. The fire testing results of seven batches of HSC and NSC are presented and discussed. The test results indicated that the post-fire re-curing results in substantial strength and durability recovery, and its extent depends upon the types of concrete, temperature level, and re-curing age. The fire tests also showed that violent explosive reduced the risk of HSC explosive spalling. The surface crack widths were also reduced during the re-curing process, and in most cases, they were found within the maximum limits specified by the American Concrete Institute (ACI) building code., Numerical models are developed herein to investigate the behavior in fire of RC columns and beams. The models have been validated against fire test data available in literature, and used to conduct parametric studies, which focused on the size effect on fire resistance of RC columns, and the effect of concrete cover thickness on fire endurance of RC beams. Simplified calculation methods have been developed to predict the load capacity of fire damaged RC columns/beams. This method is validated by five case studies, including thirty-five RC columns tested by other investigators. The predicted results are compared with the experimental results, and the good agreement indicates the adequacy of the simplified method for practical engineering applications.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369189
- Subject Headings
- Reinforced concrete, Thermodynamics, Concrete, Effect of temperature on, Heat engineering, High strength concrete, Mechanical properties, Concrete, Permeability, Testing
- Format
- Document (PDF)
- Title
- Fatigue and fracture of foam cores used in sandwich composites.
- Creator
- Saenz, Elio., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This study focused on the fracture and fatigue crack growth behavior in polyvinylchloride (PVC) and polyethersulfone (PES) foams. A new sandwich double cantilever beam (DCB) test specimen was implemented. Elastic foundation and finite element analysis and experimental testing confirmed that the DCB specimen is appropriate for static and cyclic crack propagation testing of soft polymer foams. A comprehensive experimental mechanical analysis was conducted on PVC foams of densities ranging from...
Show moreThis study focused on the fracture and fatigue crack growth behavior in polyvinylchloride (PVC) and polyethersulfone (PES) foams. A new sandwich double cantilever beam (DCB) test specimen was implemented. Elastic foundation and finite element analysis and experimental testing confirmed that the DCB specimen is appropriate for static and cyclic crack propagation testing of soft polymer foams. A comprehensive experimental mechanical analysis was conducted on PVC foams of densities ranging from 45 to 100 kg/m3 and PES foams of densities ranging from 60 to 130 kg/m3. An in-situ scanning electron microscope study on miniature foam fracture specimens showed that crack propagation in the PVC foam was inter-cellular and in the PES foam, failure occurred predominately by extensional failure of vertical cell edges. Sandwich DCB specimens were loaded cyclically as well. For the PVC foams, the crack growth rates were substantially influenced by the density. For the PES foams, there was no clear indication about the influence of foam density on the crack growth rate.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352829
- Subject Headings
- Sandwich construction, Composite materials, Fibrous composites, Strains and stresses, Management, Laminated materials, Plastics, Fatigue
- Format
- Document (PDF)
- Title
- Fatigue modeling of composite ocean current turbine blade.
- Creator
- Akram, Mohammad Wasim, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The success of harnessing energy from ocean current will require a reliable structural design of turbine blade that is used for energy extraction. In this study we are particularly focusing on the fatigue life of a 3m length ocean current turbine blade. The blade consists of sandwich construction having polymeric foam as core, and carbon/epoxy as face sheet. Repetitive loads (Fatigue) on the blade have been formulated from the randomness of the ocean current associated with turbulence and...
Show moreThe success of harnessing energy from ocean current will require a reliable structural design of turbine blade that is used for energy extraction. In this study we are particularly focusing on the fatigue life of a 3m length ocean current turbine blade. The blade consists of sandwich construction having polymeric foam as core, and carbon/epoxy as face sheet. Repetitive loads (Fatigue) on the blade have been formulated from the randomness of the ocean current associated with turbulence and also from velocity shear. These varying forces will cause a cyclic variation of bending and shear stresses subjecting to the blade to fatigue. Rainflow Counting algorithm has been used to count the number of cycles within a specific mean and amplitude that will act on the blade from random loading data. Finite Element code ANSYS has been used to develop an S-N diagram with a frequency of 1 Hz and loading ratio 0.1 Number of specific load cycles from Rainflow Counting in conjunction with S-N diagram from ANSYS has been utilized to calculate fatigue damage up to 30 years by Palmgren-Miner's linear hypothesis.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2867332
- Subject Headings
- Turbines, Blades, Materials, Fatigue, Marine turbines, Mathematical models, Structural dynamics, Composite materials, Mathematical models, Sandwich construction, Fatigue
- Format
- Document (PDF)
- Title
- Degradation of the composite fiber/matrix interface in marine environment.
- Creator
- Farooq, Muhammad Umar., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Durability of the composite materials in marine environments has been investigated experimentally and with analytical and numerical methods. The main focus of this study is on the integrity of the fiber/matrix interface under seawater exposure. A single-fiber compression test specimen called the Outwater-Murphy (OM) test has been analyzed using mechanics of materials principles and linear elastic fracture mechanics. Sizing of the OM specimen was conducted so that debonding of the fiber from...
Show moreDurability of the composite materials in marine environments has been investigated experimentally and with analytical and numerical methods. The main focus of this study is on the integrity of the fiber/matrix interface under seawater exposure. A single-fiber compression test specimen called the Outwater-Murphy (OM) test has been analyzed using mechanics of materials principles and linear elastic fracture mechanics. Sizing of the OM specimen was conducted so that debonding of the fiber from the interface should be achieved prior to yielding of the matrix and global instability failure. Stress analysis of the OM specimen has been conducted from theory of elasticity and finite element analysis. A superelement technique was developed for detailed analysis of the stress state at the fiber/matrix interface. The interface stress state at the debond site in the OM specimen, i.e. at the hole edge, was identified as biaxial tension at the fiber/matrix interface. Characterization of cure and post-cure of 8084 and 510A vinlyester resins has been performed using cure shrinkage tests based on dynamic mechanical analysis and coated beam experiments. In addition, moisture absorption, swelling and the influence of moisture on the mechanical properties of the resins were determined. Testing of OM specimens consisting of a single carbon or glass fiber embedded in vinylester resin at dry conditions and after seawater exposure revealed that the debond toughness was substantially reduced after exposure of the OM specimen to seawater. C(F) did not debond. Macroscopic carbon/vinylester woven composites where the fibers were sized with F sizing were tested in shear at dry conditions and after four weeks of seawater exposure. The shear strength was very little affected after the short immersion time.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/228774
- Subject Headings
- Fibrous composites, Graphite fibers, Composite materials, Mechanical properties, Polymers, Deterioration
- Format
- Document (PDF)
- Title
- Design and finite element analysis of an ocean current turbine blade.
- Creator
- Asseff, Nicholas S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A composite 3 meter ocean current turbine blade has been designed and analyzed using Blade Element Theory (BET) and commercial Finite Element Modeling (FEM) code, ANSYS. It has been observed that using the numerical BET tool created, power production up to 141 kW is possible from a 3 bladed rotor in an ocean current of 2.5 m/s with the proposed blade design. The blade is of sandwich construction with carbon fiber skin and high density foam core. It also contains two webs made of S2-glass for...
Show moreA composite 3 meter ocean current turbine blade has been designed and analyzed using Blade Element Theory (BET) and commercial Finite Element Modeling (FEM) code, ANSYS. It has been observed that using the numerical BET tool created, power production up to 141 kW is possible from a 3 bladed rotor in an ocean current of 2.5 m/s with the proposed blade design. The blade is of sandwich construction with carbon fiber skin and high density foam core. It also contains two webs made of S2-glass for added shear rigidity. Four design cases were analyzed, involving differences in hydrodynamic shape, material properties, and internal structure. Results from the linear static structural analysis revealed that the best design provides adequate stiffness and strength to produce the proposed power without any structural failure. An Eigenvalue Buckling analysis confirmed that the blade would not fail from buckling prior to overstressed laminate failure if the loading was to exceed the Safety Factor.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/221944
- Subject Headings
- Marine turbines, Mathematical models, Fluid dynamics, Structural dynamics, Composite materials, Mathematical models
- Format
- Document (PDF)
- Title
- Detection, localization, and identification of bearings with raceway defect for a dynamometer using high frequency modal analysis of vibration across an array of accelerometers.
- Creator
- Waters, Nicholas., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis describes a method to detect, localize and identify a faulty bearing in a rotating machine using narrow band envelope analysis across an array of accelerometers. This technique is developed as part of the machine monitoring system of an ocean turbine. A rudimentary mathematical model is introduced to provide an understanding of the physics governing the vibrations caused by a bearing with a raceway defect. This method is then used to detect a faulty bearing in two setups : on a...
Show moreThis thesis describes a method to detect, localize and identify a faulty bearing in a rotating machine using narrow band envelope analysis across an array of accelerometers. This technique is developed as part of the machine monitoring system of an ocean turbine. A rudimentary mathematical model is introduced to provide an understanding of the physics governing the vibrations caused by a bearing with a raceway defect. This method is then used to detect a faulty bearing in two setups : on a lathe and in a dynamometer.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359156
- Subject Headings
- Marine turbines, Mathematical models, Vibration, Measurement, Fluid dynamics, Dynamic testing
- Format
- Document (PDF)
- Title
- Design of cathodic protection using BEM for components of the piilot ocean energy system.
- Creator
- Gantiva, Nicolas., College of Engineering and Computer Science, Florida Atlantic University, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The Center for Ocean Energy Technology at Florida Atlantic University is developing an ocean energy turbine system to investigate the feasibility of harnessing Florida's Gulf Stream current kinetic energy and transforming it into a usable form. The turbine system has components which are prone to marine corrosion given the materials they are made of and to the harsh environment they will be exposed to. This study assumes a two-part system composed of a coating system acting as a barrier and...
Show moreThe Center for Ocean Energy Technology at Florida Atlantic University is developing an ocean energy turbine system to investigate the feasibility of harnessing Florida's Gulf Stream current kinetic energy and transforming it into a usable form. The turbine system has components which are prone to marine corrosion given the materials they are made of and to the harsh environment they will be exposed to. This study assumes a two-part system composed of a coating system acting as a barrier and sacrificial anode cathodic protection which polarizes the metal structures to a potential value where corrosion is significantly reduced. Several configurations (varying in anode quantity, size and location) were considered in order to cathodically protect the structures with various coating qualities (poor, good and excellent). These cases were modeled and simulated via Boundary Element Method software and analyzed so as to assess the most appropriate design.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2684309
- Subject Headings
- Cathodic protection, Corrosion and anti-corrosives, Finite element method, Seawater corrosion, Prevention
- Format
- Document (PDF)
- Title
- Design of hydrodynamic test facility and scaling procedure for ocean current renewable energy devices.
- Creator
- Valentine, William., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Simulations have been carried out to validate a hydrokinetic energy system non-dimensional scaling procedure. The requirements for a testing facility intended to test such devices will be determined from the results of the simulations. There are 6 simulations containing 3 prototype systems and 2 possible model facility depths to give a range of results. The first 4 tests are conducted using a varying current profile, while the last 2 tests use a constant current profile of 1.6 m/s. The 3...
Show moreSimulations have been carried out to validate a hydrokinetic energy system non-dimensional scaling procedure. The requirements for a testing facility intended to test such devices will be determined from the results of the simulations. There are 6 simulations containing 3 prototype systems and 2 possible model facility depths to give a range of results. The first 4 tests are conducted using a varying current profile, while the last 2 tests use a constant current profile of 1.6 m/s. The 3 prototype systems include a: 6 m spherical buoy, a 12 m spherical buoy and a turbine component system. The mooring line used for the simulations is a 6x19 Wire Rope Wire Core of diameter 100 mm and length 1000 m. The simulations are implemented using Orcaflex to obtain the dynamic behavior of the prototype and scaled system.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3356013
- Subject Headings
- Ocean energy resources, Research, Renewable energy sources, Sustainable engineering, Materials, Deep-sea moorings
- Format
- Document (PDF)
- Title
- Complete thermal design and modeling for the pressure vessel of an ocean turbine -: a numerical simulation and optimization approach.
- Creator
- Kaiser, Khaled., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis is an approach of numerical optimization of thermal design of the ocean turbine developed by the Centre of Ocean Energy and Technology (COET). The technique used here is the integrated method of finite element analysis (FEA) of heat transfer, artificial neural network (ANN) and genetic algorithm (GA) for optimization purposes.
- Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369194
- Subject Headings
- Thermal analysis, Computer programs, Heat exchangers, Design and construction, Marine turbines, Testing, Mathematical models, Fluid dynamics
- Format
- Document (PDF)
- Title
- Effect of wind on near-shore breaking waves.
- Creator
- Schaffer, Faydra., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The aim of this project is to identify the effect of wind on near-shore breaking waves. A breaking wave was created using a simulated beach slope configuration. Testing was done on two different beach slope configurations. The effect of offshore winds of varying speeds was considered. Waves of various frequencies and heights were considered. A parametric study was carried out. The experiments took place in the Hydrodynamics lab at FAU Boca Raton campus. The experimental data validates the...
Show moreThe aim of this project is to identify the effect of wind on near-shore breaking waves. A breaking wave was created using a simulated beach slope configuration. Testing was done on two different beach slope configurations. The effect of offshore winds of varying speeds was considered. Waves of various frequencies and heights were considered. A parametric study was carried out. The experiments took place in the Hydrodynamics lab at FAU Boca Raton campus. The experimental data validates the knowledge we currently know about breaking waves. Offshore winds effect is known to increase the breaking height of a plunging wave, while also decreasing the breaking water depth, causing the wave to break further inland. Offshore winds cause spilling waves to react more like plunging waves, therefore increasing the height of the spilling wave while consequently decreasing the breaking water depth.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2979378
- Subject Headings
- Wave motion, Theory of, Ocean waves, Climatology, Computational fluid dynamics
- Format
- Document (PDF)
- Title
- Emission characteristics of a liquid spray sudden expansion combustor using computational fluid dynamics.
- Creator
- Rodriguez, Daniel, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A sudden expansion combustor (SUE) is analyzed using computation fluid dynamics (CFD). CO emissions and NOx emissions are computed for various operating conditions of the SUE combustor using a can type and an annular type geometrical configurations. The goal of this thesis is to see if the SUE combustor is a viable alternative to conventional combustors which utilize swirlers. It is found that for the can type combustor the NOx emissions were quite low compared to other combustor types but...
Show moreA sudden expansion combustor (SUE) is analyzed using computation fluid dynamics (CFD). CO emissions and NOx emissions are computed for various operating conditions of the SUE combustor using a can type and an annular type geometrical configurations. The goal of this thesis is to see if the SUE combustor is a viable alternative to conventional combustors which utilize swirlers. It is found that for the can type combustor the NOx emissions were quite low compared to other combustor types but the CO emissions were fairly high. The annular combustor shows better CO emissions compared to the can type, but the CO emissions are still high compared to other combustors. Emissions can be improved by providing better mixing in the primary combustion zone. The SUE combustor design needs to be further refined in order for it to be a viable alternative to conventional combustors with swirlers.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362574
- Subject Headings
- Fluid dynamics, Data processing, Fluid dynamics, Mathematical models, Computational fluid dynamics, Diffusers, Fluid dynamics
- Format
- Document (PDF)
- Title
- Global distribution of ocean thermal energy conversion (OTEC) resources and applicability in U.S. waters near Florida.
- Creator
- Rauchenstein, Lynn., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The following study explores the worldwide spatial and temporal distributions of electrical power that can be extracted from the ocean's stored solar energy via the process of closed-cycle ocean thermal energy conversion (OTEC). Special emphasis is placed on resources surrounding the state of Florida. The study combines oceanographic input from a state-of-the-art ocean circulation model, the Hybrid Coordinate Ocean Model, with a state-of-the-industry OTEC plant model to predict achievable...
Show moreThe following study explores the worldwide spatial and temporal distributions of electrical power that can be extracted from the ocean's stored solar energy via the process of closed-cycle ocean thermal energy conversion (OTEC). Special emphasis is placed on resources surrounding the state of Florida. The study combines oceanographic input from a state-of-the-art ocean circulation model, the Hybrid Coordinate Ocean Model, with a state-of-the-industry OTEC plant model to predict achievable power values across the world. These power predictions are then constrained by local replenishment rates of cold deep sea water to provide an upper limit to the sustainable OTEC resource. Next, the geographic feasibility of OTEC-coupled and OTEC-independent sea water cooling (air conditioning and refrigeration) are explored. Finally, the model data is validated against in situ oceanic measurements to ensure the quality of the predictions.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358968
- Subject Headings
- Ocean energy resources, Ocean engineering, Geothermal energy, Power resources
- Format
- Document (PDF)
- Title
- Aerodynamic analysis of a propeller in a turbulent boundary layer flow.
- Creator
- Lachowski, Felipe Ferreira., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Simulating the exact chaotic turbulent flow field about any geometry is a dilemma between accuracy and computational resources, which has been continuously studied for just over a hundred years. This thesis is a complete walk-through of the entire process utilized to approximate the flow ingested by a Sevik-type rotor based on solutions to the Reynolds Averaged Navier-Stokes equations (RANS). The Multiple Reference Frame fluid model is utilized by the code of ANSYS-FLUENT and results are...
Show moreSimulating the exact chaotic turbulent flow field about any geometry is a dilemma between accuracy and computational resources, which has been continuously studied for just over a hundred years. This thesis is a complete walk-through of the entire process utilized to approximate the flow ingested by a Sevik-type rotor based on solutions to the Reynolds Averaged Navier-Stokes equations (RANS). The Multiple Reference Frame fluid model is utilized by the code of ANSYS-FLUENT and results are validated by experimental wake data. Three open rotor configurations are studied including a uniform inflow and the rotor near a plate with and without a thick boundary layer. Furthermore, observations are made to determine the variation in velocity profiles of the ingested turbulent flow due to varying flow conditions.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3360798
- Subject Headings
- Acoustical engineering, Boundary layer control, Multiphase flow, Mathematical models, Fluid mechanics, Mathematical models, Turbulence, Mathematical models, Computatioinal fluid dynamics
- Format
- Document (PDF)
- Title
- Accelerated curing of concrete with high volume pozzolans - resistivity, diffusivity and compressive strength.
- Creator
- Liu, Yanbo., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This investigation presents results of the temperature effect on durability properties (resistivity and diffusivity) and compressive strength of concrete with pozzolans, and the effect of pozzolanic admixtures on microstructure and chemical compositions of concrete pore solution. ... Temperature dependence of electrical resistivity and chloride diffusivity was studied by dynamic temperature tests. Accelerated curing regimes involving curing concrete specimens in 35À C lime water with...
Show moreThis investigation presents results of the temperature effect on durability properties (resistivity and diffusivity) and compressive strength of concrete with pozzolans, and the effect of pozzolanic admixtures on microstructure and chemical compositions of concrete pore solution. ... Temperature dependence of electrical resistivity and chloride diffusivity was studied by dynamic temperature tests. Accelerated curing regimes involving curing concrete specimens in 35À C lime water with different durations were tested. Compressive strength test, resisivity measurement and rapid chloride migration (RCM) tests were performed. A leaching method was used to measure pH and conductivity of concrete pore solution. ... The accelerated curing regimes were found to increase the compressive strength and resistance to chloride ion penetration at short-term and long-term. With the developed correlation between resistivity and migration coefficients, it is possible to employ the resistivity measurement as an alternative or replacement of the RCM test to evaluate resistance of chloride ion penetration of concrete. Pozzolanic admixtures were found to decrease both pH and conductivity of concrete pore solution as the replacement ratio increased. Moreover, the migration coefficients were found to be greatly correlated to the microstructure properties of concrete, such as porosity, formation factor and tortuosity.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358603
- Subject Headings
- Pavements, Concrete, Additives, Quality control, Waste products as road materials, Reinforced concrete, Corrosion, Testing
- Format
- Document (PDF)
- Title
- Acoustic tracking of an unmanned underwater vehicle using a passive ultrashort baseline array and a single long baseline beacon.
- Creator
- Seaton, Kyle L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis discusses a new approach to tracking the REMUS 100 AUV using a modified version of the Florida Atlantic University (FAU) ultrashort baseline (USBL) acoustic positioning system (APS). The REMUS 100 is designed to utilize a long baseline (LBL) acoustic positioning system to obtain positioning data in mid-mission. If the placement of one of the transponders of the LBL field is known, then tracking the position of the REMUS 100 AUV using a passive USBL array is possible. As part of...
Show moreThis thesis discusses a new approach to tracking the REMUS 100 AUV using a modified version of the Florida Atlantic University (FAU) ultrashort baseline (USBL) acoustic positioning system (APS). The REMUS 100 is designed to utilize a long baseline (LBL) acoustic positioning system to obtain positioning data in mid-mission. If the placement of one of the transponders of the LBL field is known, then tracking the position of the REMUS 100 AUV using a passive USBL array is possible. As part of the research for this thesis, the FAU USBL system was used to find a relative range between the REMUS 100 ranger and a LBL transponder. This relative range was then combined with direction of arrival information and LBL field component position information to determine an absolute position of the REMUS 100 ranger. The outcome was the demonstration of a passive USBL based tracking system.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3361057
- Subject Headings
- Underwater acoustic telemetry, Acoustic velocity meters, Array processors, Acoustical engineering, Adaptive signal processing
- Format
- Document (PDF)
