Current Search: Computer Simulation (x)
View All Items
Pages
- Title
- Software development of a hardware-in-the-loop simulation and a three-dimensional viewer for autonomous underwater vehicles.
- Creator
- Mahieu, Frederi., Florida Atlantic University, An, Edgar, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis describes the development of the hardware-in-the-loop simulation for FAU Autonomous Underwater Vehicles. The development was based on the existing simulation platform. For more efficiency and flexibility, this simulation package was ported to Linux. The hardware-in-the-loop simulation enables developers to connect the vehicle directly to a remote simulator. This kind of simulation is used to test the actual software components embedded in the vehicle system. The simulation package...
Show moreThis thesis describes the development of the hardware-in-the-loop simulation for FAU Autonomous Underwater Vehicles. The development was based on the existing simulation platform. For more efficiency and flexibility, this simulation package was ported to Linux. The hardware-in-the-loop simulation enables developers to connect the vehicle directly to a remote simulator. This kind of simulation is used to test the actual software components embedded in the vehicle system. The simulation package was enhanced by the addition of a 3D viewer. This thesis describes the whole development process, from feasibility study and implementation to qualification phases. This viewer is platform independent and designed to be connected to the simulator. It renders the AUV moving in a virtual environment. This tool can be used during all development steps, from tuning phases to post-mission analysis.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/15778
- Subject Headings
- Oceanographic submersibles--Computer simulation, Computer software--Development, Simulation methods, Three-dimensional display systems
- Format
- Document (PDF)
- Title
- Development of an intelligent fuzzy obstacle avoidance system using SONAR modeling and simulation.
- Creator
- Bouxsein, Philip A., Florida Atlantic University, An, Edgar
- Abstract/Description
-
Response time to a threat or incident for coastline security is an area needing improvement. Currently, the U.S. Coast Guard is tasked with monitoring and responding to threats in coastal and port environments using boats or planes, and SCUBA divers. This can significantly hinder the response time to an incident. A solution to this problem is to use autonomous underwater vehicles (AUVs) to continuously monitor a port. The AUV must be able to navigate the environment without colliding into...
Show moreResponse time to a threat or incident for coastline security is an area needing improvement. Currently, the U.S. Coast Guard is tasked with monitoring and responding to threats in coastal and port environments using boats or planes, and SCUBA divers. This can significantly hinder the response time to an incident. A solution to this problem is to use autonomous underwater vehicles (AUVs) to continuously monitor a port. The AUV must be able to navigate the environment without colliding into objects for it to operate effectively. Therefore, an obstacle avoidance system (OAS) is essential to the activity of the AUV. This thesis describes a systematic approach to characterize the OAS performance in terms of environments, obstacles, SONAR configuration and signal processing methods via modeling and simulation. A fuzzy logic based OAS is created using the simulation. Subsequent testing of the OAS demonstrates its effectiveness in unknown environments.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13390
- Subject Headings
- Fuzzy logic, Submersibles--Automatic control, Neural networks (Computer science), Underwater acoustics--Computer simulation, Sonar--Computer simulation
- Format
- Document (PDF)
- Title
- Longitudinal transport in a coastal lagoon.
- Creator
- Smith, Ned P.
- Date Issued
- 1990
- PURL
- http://purl.flvc.org/FCLA/DT/3173015
- Subject Headings
- Lagoons, Estuarine oceanography, Ocean circulation, Atmospheric circulation, Computer simulation
- Format
- Document (PDF)
- Title
- Computer simulation of air-estuary thermal energy fluxes.
- Creator
- Smith, Ned P.
- Date Issued
- 1980
- PURL
- http://purl.flvc.org/FCLA/DT/3353728
- Subject Headings
- Estuaries--Research, Computer simulation, Meteorological data, Thermal flux, Air
- Format
- Document (PDF)
- Title
- Computer simulation of tide-induced residual transport in a coastal lagoon.
- Creator
- Smith, Ned P.
- Date Issued
- 1990
- PURL
- http://purl.flvc.org/FCLA/DT/3172975
- Subject Headings
- Computer simulation, Tidal currents, Ocean currents, Sediment transport, Lagoons
- Format
- Document (PDF)
- Title
- Determination of wetland impact due to groundwater drawdown: The application of aerial photo-interpretation, GIS analysis, and groundwater modeling.
- Creator
- Hindle, Tobin, Florida Atlantic University, Marsh, G. Alex
- Abstract/Description
-
Aerial photo-interpretation, GIS analysis, and groundwater modeling were employed to determine the impact of permitted groundwater withdrawal, primarily for agricultural irrigation, on protected wetland communities within Jonathan Dickinson State Park (JDSP), Martin County Florida. Since 1952, much of the wetland habitat has succeeded to terrestrial pine flatwoods in the southwestern section of the wilderness preserve of JDSP. The drying trend can not be linked to natural hydrologic impact,...
Show moreAerial photo-interpretation, GIS analysis, and groundwater modeling were employed to determine the impact of permitted groundwater withdrawal, primarily for agricultural irrigation, on protected wetland communities within Jonathan Dickinson State Park (JDSP), Martin County Florida. Since 1952, much of the wetland habitat has succeeded to terrestrial pine flatwoods in the southwestern section of the wilderness preserve of JDSP. The drying trend can not be linked to natural hydrologic impact, but strongly correlates to groundwater drawdown calculated using a three-dimensional groundwater computer model.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15465
- Subject Headings
- Groundwater flow--Computer simulation, Geographic information systems, Wetland hydrology
- Format
- Document (PDF)
- Title
- Micro-model for paper.
- Creator
- Lu, Wentao, Florida Atlantic University, Carlsson, Leif A., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
An aggregate (mosaic) model is proposed to represent the structure of paper and model the mechanical properties. The model treats paper as an aggregate of three subregions of characteristic materials, viz. bonded regions, unbonded regions (free fiber segments) and voids. A computer simulation based on the Monte Carlo method is performed to generate random and oriented paper sheets and input parameters for the aggregate model. The number of fiber crossings, total bonded area, average free...
Show moreAn aggregate (mosaic) model is proposed to represent the structure of paper and model the mechanical properties. The model treats paper as an aggregate of three subregions of characteristic materials, viz. bonded regions, unbonded regions (free fiber segments) and voids. A computer simulation based on the Monte Carlo method is performed to generate random and oriented paper sheets and input parameters for the aggregate model. The number of fiber crossings, total bonded area, average free fiber segment length and volume fractions of bonded material and free fiber segments and apparent sheet density are obtained from the statistical geometry description of the paper structure. The upper and lower bounds on the elastic moduli and moisture swelling coefficients of void-free paper are derived based on anisotropic elasticity theory and a fiber orientation distribution parameter. The finite element method is applied to generate effective elastic moduli and moisture swelling coefficients of the aggregate model consisting of fiber crossings and segments, but no voids. The elastic moduli of paper so obtained are corrected for the voids present in paper. The predictions are compared with previously published experimental results, and it is demonstrated that the results generally fall within the theoretical bounds. The mosaic model was shown to approximate the mechanical properties of paper.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/15064
- Subject Headings
- Paper, Papermaking, Monte Carlo method--Computer simulation
- Format
- Document (PDF)
- Title
- Obstacle detection by a forward-looking sonar integrated in an autonomous underwater vehicle.
- Creator
- Martin, Antoine., Florida Atlantic University, An, Edgar, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis describes the implementation of a commercially available forward looking sonar (FLS) in an autonomous underwater vehicle (AUV) modified for the task of reactive obstacle detection. Any obstacle lying in the vehicle's path is a potential mission-terminating threat. Inclusion of a forward looking sensor would provide valuable information to the AUV. Threat assessment and navigation would use this information in order to avoid obstacles. The system used for this project is an 8...
Show moreThis thesis describes the implementation of a commercially available forward looking sonar (FLS) in an autonomous underwater vehicle (AUV) modified for the task of reactive obstacle detection. Any obstacle lying in the vehicle's path is a potential mission-terminating threat. Inclusion of a forward looking sensor would provide valuable information to the AUV. Threat assessment and navigation would use this information in order to avoid obstacles. The system used for this project is an 8-element transducer FLS at 200 kHz. The sonar control software is done in DOS on a dedicated personal computer in a PC/104 form factor. A variable cell-size grid occupancy search method is used to detect objects in the vehicle path. This thesis describes how this sonar is used for the obstacle detection task (software), how it is integrated (hardware and network) in the AUV and what are the results obtained with the system.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12691
- Subject Headings
- Oceanographic submersibles--Computer simulation, Sonar, Underwater navigation
- Format
- Document (PDF)
- Title
- Real time method for remote measurement of compressional wave attenuation.
- Creator
- DeBruin, Darryl L., Florida Atlantic University, Schock, Steven G.
- Abstract/Description
-
An acoustic measurement system is developed to estimate the compressional wave attenuation of marine sediments in real time. A chirp sonar transmits filtered digital reflection data to a signal processing computer that processes the data on an AT&T DSP32C chip. The signal processing computer estimates and displays the center frequency of the processed pulse as it is attenuated by the ocean sediments. Wavelet modelling establishes the relationship between the center frequency shift and...
Show moreAn acoustic measurement system is developed to estimate the compressional wave attenuation of marine sediments in real time. A chirp sonar transmits filtered digital reflection data to a signal processing computer that processes the data on an AT&T DSP32C chip. The signal processing computer estimates and displays the center frequency of the processed pulse as it is attenuated by the ocean sediments. Wavelet modelling establishes the relationship between the center frequency shift and relaxation time, from which the sediment type and compressional wave attenuation are determined. Frequency contours from two different data sites demonstrate that the system is able to reliably estimate sediment type and compressional wave attenuation. Error introduced by noise is below 1% for noise levels less than 0.1 of the normalized processed signal. Random error in the estimates is minimized by determining reliable frequency values and by ensemble averaging the values.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14824
- Subject Headings
- Marine sediments--Acoustic properties, Signal processing--Computer simulation
- Format
- Document (PDF)
- Title
- Variations in model discretization methodology and its effects upon groundwater modeling.
- Creator
- Whitman, Jason L., Florida Atlantic University, Restrepo, Jorge I.
- Abstract/Description
-
It is a fundamental supposition in groundwater modeling that as the discretization of a model domain is increased, the model's precision increases accordingly (Anderson and Woessner, 1992). However, the quantifiable amount and specific circumstances of that benefit remain unclear. The purpose of this research is to examine the output variations discerned as a result of applying successively coarsened discretization scenarios to a groundwater model test case. The test models, comprised of both...
Show moreIt is a fundamental supposition in groundwater modeling that as the discretization of a model domain is increased, the model's precision increases accordingly (Anderson and Woessner, 1992). However, the quantifiable amount and specific circumstances of that benefit remain unclear. The purpose of this research is to examine the output variations discerned as a result of applying successively coarsened discretization scenarios to a groundwater model test case. The test models, comprised of both regular (square) and irregular forty-four individual model output solutions. Detailed analysis of the piezometric head values, mass balance flow terms, and solution convergence times for each model run provides valuable insight into the complex relationship existing between spatial discretization and its effect upon model output values. Consequently, the aforementioned relationship proves to be highly complex, often affecting multiple model parameters in dissimilar manners while maintaining consistency in others.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15750
- Subject Headings
- Groundwater flow--Computer simulation, Groundwater flow--Mathematical models
- Format
- Document (PDF)
- Title
- Interacting in electronic space: Group dynamics resulting from individual change.
- Creator
- L'Herrou, Todd Alan, Florida Atlantic University, Latane, Bibb, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
Three studies use interaction in groups to test macro-level phenomena of the type predicted by computer simulations of dynamic social impact theory, an interactive, reciprocal, and recursive extension of Latane's (1981) theory of social impact, which specifies how individuals are affected by their social environment. A key prediction of dynamic social impact theory is that such phenomena as clustering and polarization of attitudes will emerge from social interactions among spatially...
Show moreThree studies use interaction in groups to test macro-level phenomena of the type predicted by computer simulations of dynamic social impact theory, an interactive, reciprocal, and recursive extension of Latane's (1981) theory of social impact, which specifies how individuals are affected by their social environment. A key prediction of dynamic social impact theory is that such phenomena as clustering and polarization of attitudes will emerge from social interactions among spatially distributed people. Study One, using a group of 24 people corresponding with their neighbors about an attitudinal topic, found both substantial polarization and a suggestive tendency toward clustering. Studies Two and Three, using 192 people organized into 48 24-person groups, provide strong empirical support for the emergence of clustering and incomplete polarization, and extend the findings to two alternative spatial structures. As predicted, a control geometry, involving random connections without any spatial organization, failed to produce clustering. Directions for future research are discussed.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14821
- Subject Headings
- Human behavior--Computer simulation, Social interaction, Social groups
- Format
- Document (PDF)
- Title
- Large-scale molecular dynamics simulations of semiconductor nanostructures.
- Creator
- Cornwell, Charles F., Florida Atlantic University, Wille, Luc T.
- Abstract/Description
-
Classical trajectory molecular dynamics methods are used to investigate the critical strain of single-walled carbon nanotubes ("SWT") and the strength and extent of the interactions between 3D Ge structures on the surface of Si(001). The discrete model is capable of giving some insight into the critical strain of the SWT's beyond the limits of the continuous model and allow us to investigate the effects of lattice distortion due to the placement of Ge structures on the surface of a Si...
Show moreClassical trajectory molecular dynamics methods are used to investigate the critical strain of single-walled carbon nanotubes ("SWT") and the strength and extent of the interactions between 3D Ge structures on the surface of Si(001). The discrete model is capable of giving some insight into the critical strain of the SWT's beyond the limits of the continuous model and allow us to investigate the effects of lattice distortion due to the placement of Ge structures on the surface of a Si substrate. Total energy calculations performed using classical three-body interatomic potentials with appropriate boundary conditions for each case are used to investigate the two systems. We discuss the development of a parallel code to simulate short-ranged empirical potentials such as those of Stillinger and Weber, Tersoff, and Tersoff-Brenner. We then use the Tersoff potential to model C and Si/Ge system. Data collected are used to examine the behavior of the two systems.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/12614
- Subject Headings
- Molecular dynamics--Computer simulation, Nanostructured materials, Semiconductors
- Format
- Document (PDF)
- Title
- A three-dimensional forward-look sonar simulation model.
- Creator
- Gazagnaire, Julia., Florida Atlantic University, Cuschieri, Joseph M., Beaujean, Pierre-Philippe
- Abstract/Description
-
The aim of this thesis is to develop a simulation tool, The 3-D Forward-Look Sonar Simulation Model (3-D-FLSSM), for the 3-D Forward Look Sonar or equivalent that provides insight to the defining characteristics of the sonar system that affect the image quality and the data processing. The simulator includes a representation of the acoustic environment, which incorporates a flat seafloor and spherical target, both of which are assumed to a have small-scale roughness (much less than the...
Show moreThe aim of this thesis is to develop a simulation tool, The 3-D Forward-Look Sonar Simulation Model (3-D-FLSSM), for the 3-D Forward Look Sonar or equivalent that provides insight to the defining characteristics of the sonar system that affect the image quality and the data processing. The simulator includes a representation of the acoustic environment, which incorporates a flat seafloor and spherical target, both of which are assumed to a have small-scale roughness (much less than the acoustic wavelength) associated with them. The backscatter from the target and the seafloor are calculated using the Rayleigh-Rice approximation implementing Kuo's backscattering cross section. The simulator is capable of modeling targets of various shapes and sizes. The 3-D-FLSSM assumes a plane wave approximation and a constant sound velocity throughout the water column. The final product is a simulation tool with a focus on shallow water littoral acoustics, which can be used to define the sonar hardware and processing software necessary to meet various operational requirements.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13002
- Subject Headings
- Sonar--Computer simulation, Underwater acoustics, Remote submersibles
- Format
- Document (PDF)
- Title
- Spatio-temporal dynamics in the SEIRS epidemic model.
- Creator
- Mei, Lei, Florida Atlantic University, Wille, Luc T.
- Abstract/Description
-
The Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) spatial epidemic model is governed by non-linear equations with several parameters related to birth and death, contact rate, disease latency, infectious period, and recycle rate. Both continuum results and lattice results show the existing of disease persistence and critical density. The upper limit of birth and death rate is observed, power spectrum with 1/f profile is discussed. Some other models, as limiting cases of the SEIRS...
Show moreThe Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) spatial epidemic model is governed by non-linear equations with several parameters related to birth and death, contact rate, disease latency, infectious period, and recycle rate. Both continuum results and lattice results show the existing of disease persistence and critical density. The upper limit of birth and death rate is observed, power spectrum with 1/f profile is discussed. Some other models, as limiting cases of the SEIRS model, are also studied. Lower limit of birth and death rate for the models without recycle rate has also obtained. Finally two general rules governing epidemic models are summarized. Visualization is available on our web site http://www.cse.fau.edu/~lmei/simulation.html
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15633
- Subject Headings
- Epidemiology--Mathematical models, Demography, Epidemics--Computer simulation
- Format
- Document (PDF)
- Title
- SIMULATION STUDY OF FLOW-CONTROL IN A TOKEN-RING LOCAL AREA NETWORK.
- Creator
- BALACHANDRAN, CHITRA., Florida Atlantic University, Ilyas, Mohammad
- Abstract/Description
-
This thesis deals with simulation of flow control in token-ring local area networks. The primary emphasis of this simulation study is to observe the effects of token holding time on the performance of the network. Token holding time is adjusted to account for two types of service disciplines: gated and limited. Network performance for these two service disciplines is compared to determine which one of the two gives a relatively better performance. Besides throughput and delay, a more compact...
Show moreThis thesis deals with simulation of flow control in token-ring local area networks. The primary emphasis of this simulation study is to observe the effects of token holding time on the performance of the network. Token holding time is adjusted to account for two types of service disciplines: gated and limited. Network performance for these two service disciplines is compared to determine which one of the two gives a relatively better performance. Besides throughput and delay, a more compact form of performance measure called "power", has also been used in the study . Power is simply a ratio of throughput and delay . This study has shown that the token holding time has a significant effect on the performance of a local area network . Simulation results of this study are presented in terms of throughput, delay, power, token circulation time and efficiency/overhead versus offered load. The results are presented in the form of graphs.
Show less - Date Issued
- 1986
- PURL
- http://purl.flvc.org/fcla/dt/14311
- Subject Headings
- Local area networks (Computer networks)--Simulation methods
- Format
- Document (PDF)
- Title
- Thermocline tracking using an upgraded ocean explorer autonomous underwater vehicle.
- Creator
- Clabon, Mathieu., Florida Atlantic University, Dhanak, Manhar R.
- Abstract/Description
-
This thesis addresses the problem of tracking a thermocline---a layer of water showing an intense vertical temperature gradient---with an Autonomous Underwater Vehicle (AUV). One of Florida Atlantic University's Ocean Explorer (OEX) AUV has been upgraded, as part of the work described here, by integration of a standard and convenient software interface, and used in several thermocline survey experiments aimed at gathering oceanographic data relevant to thermoclines. A tool that simulates the...
Show moreThis thesis addresses the problem of tracking a thermocline---a layer of water showing an intense vertical temperature gradient---with an Autonomous Underwater Vehicle (AUV). One of Florida Atlantic University's Ocean Explorer (OEX) AUV has been upgraded, as part of the work described here, by integration of a standard and convenient software interface, and used in several thermocline survey experiments aimed at gathering oceanographic data relevant to thermoclines. A tool that simulates the longitudinal motion of the OEX through a water slice, whose temperature map is read using a simulated temperature and depth sensor, has been developed. Using this tool and information from at-sea experiments, several control methods for the OEX to track a thermocline were analyzed. In particular, two different algorithms were implemented and tested by simulation. Overall, two control algorithms have been validated, and it will soon be possible to provide the AUV with a thermocline tracking capability.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13025
- Subject Headings
- Thermoclines (Oceanography), Oceanographic submersibles--Computer simulation, Underwater navigation
- Format
- Document (PDF)
- Title
- Integrated simulator of JIT manufacturing process.
- Creator
- Li, Shuanghu., Florida Atlantic University, Mazouz, Abdel Kader, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The main objective of this research is to develop an integrated simulator which would perform as a decision support system of a Just-in-Time manufacturing process. It would permit a process designer or manufacturing engineer with no simulation expertise to define the process variables, then run the simulation program. A secondary objective is to combine in one system the key functions required by a manufacturing engineer or manager, such as the operational (real time), statistical, and...
Show moreThe main objective of this research is to develop an integrated simulator which would perform as a decision support system of a Just-in-Time manufacturing process. It would permit a process designer or manufacturing engineer with no simulation expertise to define the process variables, then run the simulation program. A secondary objective is to combine in one system the key functions required by a manufacturing engineer or manager, such as the operational (real time), statistical, and financial aspects. And also makes those function modules easy to understand and user-friendly. The integrated simulator can use animation to visualize an actual production line. A case study has been developed to verify and validate the work done.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14800
- Subject Headings
- Just-in-time systems--Computer simulation, Manufacturing processes--Automation, Simulation methods--Computer programs
- Format
- Document (PDF)
- Title
- An empirical study of combining techniques in software quality classification.
- Creator
- Eroglu, Cemal., Florida Atlantic University, Khoshgoftaar, Taghi M.
- Abstract/Description
-
In the literature, there has been limited research that systematically investigates the possibility of exercising a hybrid approach by simply learning from the output of numerous base-level learners. We analyze a hybrid learning approach upon the systems that had previously been worked with twenty-four different classifiers. Instead of relying on only one classifier's judgment, it is expected that taking into account the opinions of several learners is a wise decision. Moreover, by using...
Show moreIn the literature, there has been limited research that systematically investigates the possibility of exercising a hybrid approach by simply learning from the output of numerous base-level learners. We analyze a hybrid learning approach upon the systems that had previously been worked with twenty-four different classifiers. Instead of relying on only one classifier's judgment, it is expected that taking into account the opinions of several learners is a wise decision. Moreover, by using clustering techniques some base-level classifiers were eliminated from the hybrid learner input. We had three different experiments each with a different number of base-level classifiers. We empirically show that the hybrid learning approach generally yields better performance than the best selected base-level learners and majority voting under some conditions.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13162
- Subject Headings
- Computer software--Testing, Computer software--Quality control, Computational learning theory, Machine learning, Digital computer simulation
- Format
- Document (PDF)
- Title
- Simulation and modeling of flow field around a horizontal axis wind turbine (HAWT) using RANS method.
- Creator
- Sargsyan, Armen., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The principal objective of the proposed CFD analysis is to investigate the flow field around a horizontal axis wind turbine rotor and calculate the turbine's power. A full three dimensional computational fluid dynamics method based on Reynolds Averaged Navier Stokes approach was used in this study. The wind turbine has three blades and a rotor diameter of six meters. One third of the wind turbine rotor was modeled by means of 120o periodicity in a moving reference frame system. The power...
Show moreThe principal objective of the proposed CFD analysis is to investigate the flow field around a horizontal axis wind turbine rotor and calculate the turbine's power. A full three dimensional computational fluid dynamics method based on Reynolds Averaged Navier Stokes approach was used in this study. The wind turbine has three blades and a rotor diameter of six meters. One third of the wind turbine rotor was modeled by means of 120o periodicity in a moving reference frame system. The power coefficient curve obtained from the CFD results is compared with experimental data obtained by NREL Phase VI rotor experiment. The numerical result for the power coefficient curve shows close agreement with the experimental data. The simulation results include the velocity distribution, pressure distribution along the flow direction, turbulent wake behind the wind turbine, and the turbine's power. The discussion will also include the effect of wind speed on turbine's power.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2979383
- Subject Headings
- Wind turbines, Aerodynamics, Computer simulation, Fluid dynamics, Computational methods, Vibration (Aerodynamics)
- Format
- Document (PDF)
- Title
- Rapid distortion theory for rotor inflows.
- Creator
- Kawashima, Emilia, Glegg, Stewart A. L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
For aerospace and naval applications where low radiated noise levels are a requirement, rotor noise generated by inflow turbulence is of great interest. Inflow turbulence is stretched and distorted as it is ingested into a thrusting rotor which can have a significant impact on the noise source levels. This thesis studies the distortion of subsonic, high Reynolds number turbulent flow, with viscous effects ignored, that occur when a rotor is embedded in a turbulent boundary layer. The analysis...
Show moreFor aerospace and naval applications where low radiated noise levels are a requirement, rotor noise generated by inflow turbulence is of great interest. Inflow turbulence is stretched and distorted as it is ingested into a thrusting rotor which can have a significant impact on the noise source levels. This thesis studies the distortion of subsonic, high Reynolds number turbulent flow, with viscous effects ignored, that occur when a rotor is embedded in a turbulent boundary layer. The analysis is based on Rapid Distortion Theory (RDT), which describes the linear evolution of turbulent eddies as they are stretched by a mean flow distortion. Providing that the gust does not distort the mean flow streamlines the solution for a mean flow with shear is found to be the same as the solution for a mean potential flow with the addition of a potential flow gust. By investigating the inflow distortion of small-scale turbulence for various simple flows and rotor inflows with weak shear, it is shown that RDT can be applied to incompressible shear flows to determine the flow distortion. It is also shown that RDT can be applied to more complex flows modeled by the Reynolds Averaged Navier Stokes (RANS) equations.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004030
- Subject Headings
- Computational fluid dynamics, Fluid dynamic measurements, Fluid mechanics -- Mathematical models, Turbulence -- Computer simulation, Turbulence -- Mathematical models
- Format
- Document (PDF)