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 Title
 TWODIMENSIONAL MODELING OF A SOLAR POND.
 Creator
 CANCIO, GUILLERMO LEOPOLDO., Florida Atlantic University, Duyar, Ahmet
 Abstract/Description

A twodimensional mathematical model is developed to analyze the thermal behavior of salt gradient solar ponds. This model can be used to evaluate the suitability of solar ponds for space heating and power generation as well as the thermal storage capability of the ground. The solar pond model adopted consists of an upper nonconvective zone and a lower convective zone. This model incorporates detailed representation of surface and ground heat losses. Solutions to the energy equation are...
Show moreA twodimensional mathematical model is developed to analyze the thermal behavior of salt gradient solar ponds. This model can be used to evaluate the suitability of solar ponds for space heating and power generation as well as the thermal storage capability of the ground. The solar pond model adopted consists of an upper nonconvective zone and a lower convective zone. This model incorporates detailed representation of surface and ground heat losses. Solutions to the energy equation are obtained for both the pond and the ground. The energy equation for the lower convective zone is used to determine the energy that can be extracted from the pond.
Show less  Date Issued
 1984
 PURL
 http://purl.flvc.org/fcla/dt/14174
 Subject Headings
 Solar ponds, Energy storage
 Format
 Document (PDF)
 Title
 Development of a simplified model of the Space Shuttle main engine.
 Creator
 Srinivasan, T. D., Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

Accurate representation of the dynamic behaviour of the Space Shuttle Main Engine (SSME) is required for various diagnostic, design and evaluation purposes. A complete nonlinear dynamic simulation of the SSME developed by the Rocketdyne Division of the Rockwell International Corporation is difficult to use due to its size and complexity, hence the need to obtain a simplified model of the SSME to generate data describing the normal modes of operation in real time is relevant and also the...
Show moreAccurate representation of the dynamic behaviour of the Space Shuttle Main Engine (SSME) is required for various diagnostic, design and evaluation purposes. A complete nonlinear dynamic simulation of the SSME developed by the Rocketdyne Division of the Rockwell International Corporation is difficult to use due to its size and complexity, hence the need to obtain a simplified model of the SSME to generate data describing the normal modes of operation in real time is relevant and also the objective of this thesis. The process involved in obtaining such a model are: (1) To determine the point models at various operating points and (2) To obtain a comprehensive piecewise linear model by regressing the parameters of the point models with variables describing the operating points. The comprehensive model obtained by using such a scheme is presented along with the point models. The nonlinearities inherent in the engine's operation are modelled as separate blocks and are added to linearized model. Finally the validity of the linked model is demonstrated with suitable test signals.
Show less  Date Issued
 1990
 PURL
 http://purl.flvc.org/fcla/dt/14644
 Subject Headings
 Space shuttlesMotorsModels
 Format
 Document (PDF)
 Title
 Development of a discrete time multivariable system identification technique.
 Creator
 Saravanan, Natarajan, Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

An identification scheme which can be used for discrete time multiinput multioutput time invariant systems is presented. The identification scheme involves two steps; (1) The identification of a set of invariant indices (Structure identification) and (2) The estimation of the parameters of the system (Parametric identification). The technique utilizes a canonical representation of a system which is based on the notion of output injection. This canonical form is dependent on a chosen real...
Show moreAn identification scheme which can be used for discrete time multiinput multioutput time invariant systems is presented. The identification scheme involves two steps; (1) The identification of a set of invariant indices (Structure identification) and (2) The estimation of the parameters of the system (Parametric identification). The technique utilizes a canonical representation of a system which is based on the notion of output injection. This canonical form is dependent on a chosen real number alpha and is therefore called the alphacanonical form. Least square estimation technique is used for parameter estimation. The offline version of this identification scheme is presented here. This scheme is then used to generate a linear model of the Space Shuttle Main Engine at the operating point corresponding to the 100% power level from the nonlinear dynamic engine simulation.
Show less  Date Issued
 1989
 PURL
 http://purl.flvc.org/fcla/dt/14558
 Subject Headings
 System identification, Space shuttlesPropulsion systemsMathematical models
 Format
 Document (PDF)
 Title
 Fault detection and diagnosis of the T700 helicopter engine.
 Creator
 Kurtkaya, Mehmet Hamit., Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

This thesis presents the design of a fault detection and diagnosis system for the T700 helicopter engine. Fault refers to a malfunction that degrades the performance of a system. Fault parameter estimation approach has been followed to accomplish this task along with the hypothesis testing for isolation purposes. Fault detection and diagnosis modules have been written in FORTRAN and run online with the engine simulation. Fault detection and diagnosis system has been tested for sensor bias,...
Show moreThis thesis presents the design of a fault detection and diagnosis system for the T700 helicopter engine. Fault refers to a malfunction that degrades the performance of a system. Fault parameter estimation approach has been followed to accomplish this task along with the hypothesis testing for isolation purposes. Fault detection and diagnosis modules have been written in FORTRAN and run online with the engine simulation. Fault detection and diagnosis system has been tested for sensor bias, sensor multiplicative fault and bias in the actuation signal. The results of these experiments are displayed at the end.
Show less  Date Issued
 1992
 PURL
 http://purl.flvc.org/fcla/dt/14788
 Subject Headings
 HelicoptersMotorsReliability, HelicoptersTestingData processing
 Format
 Document (PDF)
 Title
 A FEASIBILITY ANALYSIS OF SOLAR POND POWER GENERATION CONCEPT IN THE STATE OF FLORIDA (DESIGN).
 Creator
 PEANA, STEFAN., Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

This study investigates the technical feasibility of solar pond power generation in the state of Florida. A onedimensional model is used to analyze three different modes of operation of the pond as follows: The steady state analysis determines the maximum overall efficiency of the pond, optimum load and optimum brine temperature to be extracted. The steady periodic analysis determines the performances of the pond subjected to seasonal variation. The transient analysis determines the time...
Show moreThis study investigates the technical feasibility of solar pond power generation in the state of Florida. A onedimensional model is used to analyze three different modes of operation of the pond as follows: The steady state analysis determines the maximum overall efficiency of the pond, optimum load and optimum brine temperature to be extracted. The steady periodic analysis determines the performances of the pond subjected to seasonal variation. The transient analysis determines the time necessary for the pond to reach the optimum temperature. The study determines that for the Miami, Orlando, and Jacksonville locations, for a pond with 1.5 m NCZ depth using data for the state of Florida, the maximum overall efficiency is between 3.30 and 3.32 percent with an optimum load between 33 and 35 W/m2 and brine temperature to be extracted between 85 to 92°C. The above results assume that the power plant efficiency would be equal to that of a Carnot cycle efficiency. Since, in practice Carnot efficiency cannot be achieved the actual efficiency will be lower than the above values.
Show less  Date Issued
 1985
 PURL
 http://purl.flvc.org/fcla/dt/14281
 Subject Headings
 Solar pondsFloridaAnalysis
 Format
 Document (PDF)
 Title
 Residue generation techniques for failure diagnosis in linear systems.
 Creator
 Makkuni, Unni Kannan., Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

In this thesis, a comparative evaluation of some residue generation methods used for model based failure detection techniques is made. Residues are differences between the actual plant outputs and the outputs of a mathematical model describing the plant. Under a nofail condition and in the absence of noise, the residues are zero. When a failure occurs, the residues will be non zero and the nature of the residues depend on the residue generation method and the system input. The resulting...
Show moreIn this thesis, a comparative evaluation of some residue generation methods used for model based failure detection techniques is made. Residues are differences between the actual plant outputs and the outputs of a mathematical model describing the plant. Under a nofail condition and in the absence of noise, the residues are zero. When a failure occurs, the residues will be non zero and the nature of the residues depend on the residue generation method and the system input. The resulting residues are statistically analyzed to isolate the nature of the failure(s). Three methods for residue generation namely, parity relations, parameter estimation and estimation by the Kalman filter are discussed. A mathematical analysis for the basis of choosing a statistical test which depends on the system input is also presented.
Show less  Date Issued
 1990
 PURL
 http://purl.flvc.org/fcla/dt/14617
 Subject Headings
 Linear systems, System failures (Engineering)
 Format
 Document (PDF)
 Title
 An intelligent approach to system identification.
 Creator
 Saravanan, Natarajan, Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

System identification methods are frequently used to obtain appropriate models for the purpose of control, fault detection, pattern recognition, prediction, adaptive filtering and other purposes. A number of techniques exist for the identification of linear systems. However, realworld and complex systems are often nonlinear and there exists no generic methodology for the identification of nonlinear systems with unknown structure. A recent approach makes use of highly interconnected networks...
Show moreSystem identification methods are frequently used to obtain appropriate models for the purpose of control, fault detection, pattern recognition, prediction, adaptive filtering and other purposes. A number of techniques exist for the identification of linear systems. However, realworld and complex systems are often nonlinear and there exists no generic methodology for the identification of nonlinear systems with unknown structure. A recent approach makes use of highly interconnected networks of simple processing elements, which can be programmed to approximate nonlinear functions to identify nonlinear dynamic systems. This thesis takes a detailed look at identification of nonlinear systems with neural networks. Important questions in the application of neural networks for nonlinear systems are identified; concerning the excitation properties of input signals, selection of an appropriate neural network structure, estimation of the neural network weights, and the validation of the identified model. These questions are subsequently answered. This investigation leads to a systematic procedure for identification using neural networks and this procedure is clearly illustrated by modeling a complex nonlinear system; the components of the space shuttle main engine. Additionally, the neural network weights are determined by using a general purpose optimization technique known as evolutionary programming which is based on the concept of simulated evolution. The evolutionary programming algorithm is modified to include selfadapting step sizes. The effectiveness of the evolutionary programming algorithm as a general purpose optimization algorithm is illustrated on a test suite of problems including function optimization, neural network weight optimization, optimal control system synthesis and reinforcement learning control.
Show less  Date Issued
 1994
 PURL
 http://purl.flvc.org/fcla/dt/12371
 Subject Headings
 Neural networks (Computer science), System identification, Nonlinear theories, System analysis, Space shuttlesElectronic equipment, AlgorithmsComputer programs
 Format
 Document (PDF)
 Title
 DESIGN OF A ROBUST MULTIVARIABLE JET ENGINE CONTROL SYSTEM.
 Creator
 LARKIN, LOUIS JOSEPH., Florida Atlantic University, Duyar, Ahmet, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

Until recently, control design techniques for multivariable systems, such as pole placement or optimal control design, have been either too complex to be usable, or yielded designs which were liable to instability if the parameters of the plant varied from those used in the design. A technique which uses the singular values of the system transfer function matrix is now available. This technique yields control designs which are guaranteed to be robust with respect to plant parameter variations...
Show moreUntil recently, control design techniques for multivariable systems, such as pole placement or optimal control design, have been either too complex to be usable, or yielded designs which were liable to instability if the parameters of the plant varied from those used in the design. A technique which uses the singular values of the system transfer function matrix is now available. This technique yields control designs which are guaranteed to be robust with respect to plant parameter variations. This technique, combined with a novel technique for shaping the frequency responses of the singular values is used to design a control system for a gas turbine jet engine. It is shown that adjusting the crossover frequency of the open loop singular values affects the closed loop time and frequency response in the same manner that adjusting the open loop gain affects the response of a singleinput/singleoutput control system.
Show less  Date Issued
 1985
 PURL
 http://purl.flvc.org/fcla/dt/14235
 Subject Headings
 Flight control, Jet propulsionResearch
 Format
 Document (PDF)