Current Search: Offshore structures -- Dynamics (x)
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(1 - 4 of 4)
- Title
- Dynamic positioning and motion mitigation of a scaled sea basing platform.
- Creator
- Marikle, Sean P., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A 6-Degree Of Freedom (DOF) numeric model and computer simulation along with the 1/10th scale physical model of the Rapidly Deployable Stable Platform (RDSP) are being developed at Florida Atlantic University in response to military needs for ocean platforms with improved sea keeping characteristics. The RDSP is a self deployable spar platform with two distinct modes of operation enabling long distance transit and superior seakeeping. The focus of this research is the development of a Dynamic...
Show moreA 6-Degree Of Freedom (DOF) numeric model and computer simulation along with the 1/10th scale physical model of the Rapidly Deployable Stable Platform (RDSP) are being developed at Florida Atlantic University in response to military needs for ocean platforms with improved sea keeping characteristics. The RDSP is a self deployable spar platform with two distinct modes of operation enabling long distance transit and superior seakeeping. The focus of this research is the development of a Dynamic Position (DP) and motion mitigation system for the RDSP. This will be accomplished though the validation of the mathematical simulation, development of a novel propulsion system, and implementation of a PID controller. The result of this research is an assessment of the response characteristics of the RDSP that quantifies the performance of the propulsion system coupled with active control providing a solid basis for further controller development and operational testing.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/228767
- Subject Headings
- Inertial navigation systems, Mobile offshore structures, Design and construction, Wave motion, Theory of, Offshore structures, Dynamics, Feedback control systems
- Format
- Document (PDF)
- Title
- Model analysis of a mooring system for an ocean current turbine testing platform.
- Creator
- Cribbs, Allison Rose., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In response to Florida's growing energy needs and drive to develop renewable power, Florida Atlantic Universitys Center for Ocean Energy Technology (COET) plans to moor a 20 kW test turbine in the Florida Current. No permanent mooring systems for deepwater hydrokinetic turbines have been constructed and deployed, therefore little if anything is known about the performance of these moorings. To investigate this proposed mooring system, a numeric model is developed and then used to predict the...
Show moreIn response to Florida's growing energy needs and drive to develop renewable power, Florida Atlantic Universitys Center for Ocean Energy Technology (COET) plans to moor a 20 kW test turbine in the Florida Current. No permanent mooring systems for deepwater hydrokinetic turbines have been constructed and deployed, therefore little if anything is known about the performance of these moorings. To investigate this proposed mooring system, a numeric model is developed and then used to predict the static and dynamic behavior of the mooring system and attachments. The model has been created in OrcaFlex and includes two surface buoys and an operating turbine. Anchor chain at the end of the mooring line develops a catenary, providing compliance. Wind, wave, and current models are used to represent the environmental conditions the system is expected to experience and model the dynamic effects on the system. The model is then used to analyze various components of the system. The results identify that a mooring attachment point 1.25 m forward of the center of gravity on the mooring buoy is ideal, and that the OCDP and turbine tether lengths should be no shorter than 25 and 44 m, respectively. Analysis performed for the full system identify that the addition of the floats decreases the tension at the MTB attachment location by 26.5 to 29.5% for minimum current, and 0.10 to 0.31% for maximum current conditions.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2974432
- Subject Headings
- Marine turbines, Mathematical models, Structural dynamics, Rotors, Design and construction, Offshore structures, Testing
- Format
- Document (PDF)
- Title
- Finite element analysis of the visco-elastic behavior of a spray ice island.
- Creator
- Thiel, David Ted., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis presents a finite element analysis of the viscoelastic (creep) behavior of a spray ice island under its own self-weight and three levels of lateral loads. Spray ice and its use as a construction material are described in the context of other natural ice forms and the ice environment of the Beaufort Sea. The analytical results indicated that creep settlement in the absence of volumetric contraction was nominal over the course of a simulated 21-day construction period and a 79-day...
Show moreThis thesis presents a finite element analysis of the viscoelastic (creep) behavior of a spray ice island under its own self-weight and three levels of lateral loads. Spray ice and its use as a construction material are described in the context of other natural ice forms and the ice environment of the Beaufort Sea. The analytical results indicated that creep settlement in the absence of volumetric contraction was nominal over the course of a simulated 21-day construction period and a 79-day service life. The effects of the applied lateral loads were very localized and did not result in any appreciable deformations in the central working area of the structure. Some evidence of shear plane development and upward passive failure of the island perimeter was observed.
Show less - Date Issued
- 1990
- PURL
- http://purl.flvc.org/fcla/dt/14647
- Subject Headings
- Ice mechanics, Offshore structures--Dynamics, Sea ice--Beaufort Sea
- Format
- Document (PDF)
- Title
- Modeling and control of a vertically tethered marine platform using an active heave compensation system.
- Creator
- Eide, Linn., Florida Atlantic University, Driscoll, Frederick R.
- Abstract/Description
-
Technology movement toward deeper waters necessitates the control of vertically tethered systems that are used for installing, repairing, and maintaining underwater equipment. This has become an essential ingredient for the future success of the oil industry as the near-shore oil reservoirs are nearly depleted. Increased operation depths cause large oscillations and snap loadings in these longer cables. Research on this topic has been limited, and includes only top feedback control. The...
Show moreTechnology movement toward deeper waters necessitates the control of vertically tethered systems that are used for installing, repairing, and maintaining underwater equipment. This has become an essential ingredient for the future success of the oil industry as the near-shore oil reservoirs are nearly depleted. Increased operation depths cause large oscillations and snap loadings in these longer cables. Research on this topic has been limited, and includes only top feedback control. The controllers developed in this thesis utilize top, bottom and combined top and bottom feedback. They are implemented on a discrete finite element lumped mass cable model. Comparison between PID, LQG and H infinity for all feedback combinations reveal that the Hinfinity controller with both top and bottom feedback has the best performance, while LQG has a more consistent and reliable performance for all feedback cases.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13079
- Subject Headings
- Cables, Submarine--Mathematical models, Offshore structures--Dynamics, Feedback control systems, Ships--Hydrodynamics
- Format
- Document (PDF)
