You searched for subject:(model order reduction).
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Delft University of Technology
1.
Tjensvoll, Knut (author).
Optimizing the Reduced Basis Construction for Reduced-Order Mechanical Models: Automatic and efficient load case selection using Bayesian machine learning.
Degree: 2019, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:3e4a2119-0507-48ca-8aea-7fdbc3d98a64 
► Numerical simulations have become an essential part of design in every field of engineering, and the boundaries of technology are pushed further out every year.…
(more)
▼ Numerical simulations have become an essential part of design in every field of engineering, and the boundaries of technology are pushed further out every year. In structural engineering, the desire to design structures that have complex shapes or that are simply cheaper and more efficient, has necessitated the use of complex numerical simulations. This necessity is further substantiated when taking into consideration structures such as wind turbines that are subjected to extreme environmental conditions. In many cases, however, such simulations are prohibitively expensive due to complex material behaviour or the many-query nature of design optimization. The lack of knowledge and understanding of the behaviour and failure mechanisms is compensated by adopting less complex designs and/or high safety factors, which leads to less efficient and more expensive designs. In recent years, methods to circumvent such high computational costs have been developed. Acceleration techniques such as
model-
order reduction (MOR) are now widely researched, and significant developments are being made to overcome the issues of prohibitively expensive high-fidelity models. This thesis uses Proper Orthogonal Decomposition (POD) to drastically reduce the degrees of freedom of a simply supported beam that is loaded in the downwards direction along the span. The result of the MOR process is a reduced-
order model (ROM) that accurately approximates the behaviour of the full-
order model (FOM). The ROM is constructed by determining a set of basis vectors that contain compressed information of representative full-
order solutions collected in an it{offline} training phase. The goal in this thesis is so collect the information and construct the reduced basis as efficiently as possible while guaranteeing a given accuracy of the ROM. Two methods are presented to iteratively construct the reduced basis. The first one is the it{Surrogate Parameter Space} (SPS) method, where greedy sampling is performed on incrementally finer grids of points along the beam. Each individual grid is referred to as an SPS, and they are exhausted by selecting the load location that in each iteration will add the most new information to the ROM. The other method is the it{Gaussian Process Regression} (GPR). Greedy sampling using a Bayesian machine learning algorithm involving GPR is used to predict load locations along the beam that add the most new information to the ROM. A method to efficiently combine and compress information obtained in each iteration was also developed. The results showed that the SPS method is efficient to construct an accurate ROM for the beam
model in this thesis, but the GPR managed to recognize that some areas in the span did not have to be sampled as much as others. This makes GPR the more promising method for other high-fidelity models when high accuracy is desired. The results also showed that both methods depend greatly on input parameters that define how much information is kept in each iteration, and for GPR an additional…
Advisors/Committee Members: van der Meer, Frans (mentor), Rocha, Iuri (mentor), Sluijs, Bert (mentor), Bessa, Miguel (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: Model Order Reduction; Reduced Order Model; Reduced Basis; Machine Learning
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APA (6th Edition):
Tjensvoll, K. (. (2019). Optimizing the Reduced Basis Construction for Reduced-Order Mechanical Models: Automatic and efficient load case selection using Bayesian machine learning. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:3e4a2119-0507-48ca-8aea-7fdbc3d98a64
Chicago Manual of Style (16th Edition):
Tjensvoll, Knut (author). “Optimizing the Reduced Basis Construction for Reduced-Order Mechanical Models: Automatic and efficient load case selection using Bayesian machine learning.” 2019. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:3e4a2119-0507-48ca-8aea-7fdbc3d98a64.
MLA Handbook (7th Edition):
Tjensvoll, Knut (author). “Optimizing the Reduced Basis Construction for Reduced-Order Mechanical Models: Automatic and efficient load case selection using Bayesian machine learning.” 2019. Web. 07 Mar 2021.
Vancouver:
Tjensvoll K(. Optimizing the Reduced Basis Construction for Reduced-Order Mechanical Models: Automatic and efficient load case selection using Bayesian machine learning. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:3e4a2119-0507-48ca-8aea-7fdbc3d98a64.
Council of Science Editors:
Tjensvoll K(. Optimizing the Reduced Basis Construction for Reduced-Order Mechanical Models: Automatic and efficient load case selection using Bayesian machine learning. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:3e4a2119-0507-48ca-8aea-7fdbc3d98a64
Rochester Institute of Technology
2.
Cappello, Matthew.
A Model Order Reduction Method for Lightly Damped State Space Systems.
Degree: MS, Electrical Engineering, 2012, Rochester Institute of Technology
URL: https://scholarworks.rit.edu/theses/8591
► This paper introduces a model order reduction method that takes advantage of the near orthogonality of lightly damped modes in a system and the…
(more)
▼ This paper introduces a
model order reduction method that takes advantage of the near orthogonality of lightly damped modes in a system and the modal separation of diagonalized models to reduce the
model order of flexible systems in both continuous and discrete time. The
reduction method is computationally fast and cheap, not requiring any singular value decompositions or large matrix operations. Numeric solutions to the infinite time Lyapunov equations are presented, and used to solve for the observability and controllability grammians of diagonalized models. Four different modal importance calculations are produced from the diagonalized
model's grammians and are compared to the Hankel singular values of balanced
model order reduction. The frequency response functions (FRF) of the reduced diagonalized models are compared to models reduced using the balanced
reduction method. A weighted integral of the FRF error is taken as a metric for judging which
reduction method is better for each individual
model. For low
order or lightly damped higher
order systems the diagonal
reduction method results in significantly less FRF error than the balanced
model order reduction.
Advisors/Committee Members: Mark Hopkins.
Subjects/Keywords: Damped; Grammian; Model; Order; Orthogonal; Reduction
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APA (6th Edition):
Cappello, M. (2012). A Model Order Reduction Method for Lightly Damped State Space Systems. (Masters Thesis). Rochester Institute of Technology. Retrieved from https://scholarworks.rit.edu/theses/8591
Chicago Manual of Style (16th Edition):
Cappello, Matthew. “A Model Order Reduction Method for Lightly Damped State Space Systems.” 2012. Masters Thesis, Rochester Institute of Technology. Accessed March 07, 2021.
https://scholarworks.rit.edu/theses/8591.
MLA Handbook (7th Edition):
Cappello, Matthew. “A Model Order Reduction Method for Lightly Damped State Space Systems.” 2012. Web. 07 Mar 2021.
Vancouver:
Cappello M. A Model Order Reduction Method for Lightly Damped State Space Systems. [Internet] [Masters thesis]. Rochester Institute of Technology; 2012. [cited 2021 Mar 07].
Available from: https://scholarworks.rit.edu/theses/8591.
Council of Science Editors:
Cappello M. A Model Order Reduction Method for Lightly Damped State Space Systems. [Masters Thesis]. Rochester Institute of Technology; 2012. Available from: https://scholarworks.rit.edu/theses/8591
University of Waikato
3.
Shaw, Adrian Mark.
Partial Order Reduction with Compositional Verification
.
Degree: 2014, University of Waikato
URL: http://hdl.handle.net/10289/9001
► This thesis expands the usage of partial order reduction methods in reducing the state space of large models in model checking. The work done can…
(more)
▼ This thesis expands the usage of partial
order reduction methods in reducing the state space of large models in
model checking. The work done can be divided into two parts. In the first part we introduce two new ample conditions that utilise strongly connected components in place of two existing ample conditions that use cycles. We use these new conditions to optimise existing partial
order reduction verifiers and extend them to verify nonblocking properties. We also introduce two selection strategies for choosing ample event sets and an improved ample algorithm in
order to improve the efficiency of ample set computation, and investigate how the various combinations of these suggested algorithmic improvements effect several models of varying size. The second part of the thesis introduces the concept of using partial
order reduction techniques in combination with compositional verification techniques. We introduce a modified version of the silent continuation rule that makes use of the independence relationship from partial
order reduction methods and include algorithms by which they may be implemented in a
model verifier. All of the original concepts developed in this thesis are also proven correct.
Advisors/Committee Members: Malik, Robi (advisor).
Subjects/Keywords: Partial order reduction;
Model checking;
compositional verification
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APA (6th Edition):
Shaw, A. M. (2014). Partial Order Reduction with Compositional Verification
. (Masters Thesis). University of Waikato. Retrieved from http://hdl.handle.net/10289/9001
Chicago Manual of Style (16th Edition):
Shaw, Adrian Mark. “Partial Order Reduction with Compositional Verification
.” 2014. Masters Thesis, University of Waikato. Accessed March 07, 2021.
http://hdl.handle.net/10289/9001.
MLA Handbook (7th Edition):
Shaw, Adrian Mark. “Partial Order Reduction with Compositional Verification
.” 2014. Web. 07 Mar 2021.
Vancouver:
Shaw AM. Partial Order Reduction with Compositional Verification
. [Internet] [Masters thesis]. University of Waikato; 2014. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10289/9001.
Council of Science Editors:
Shaw AM. Partial Order Reduction with Compositional Verification
. [Masters Thesis]. University of Waikato; 2014. Available from: http://hdl.handle.net/10289/9001
Delft University of Technology
4.
Zimmerling, J.T. (author).
Modeling of wave propagation in open domains: A Krylov subspace approach.
Degree: 2014, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:aea44c4e-2658-474d-b9ea-c046066ac881
► Simulating electromagnetic or acoustic wave propagation in complex open structures is extremely important in many areas of science and engineering. In a wide range of…
(more)
▼ Simulating electromagnetic or acoustic wave propagation in complex open structures is extremely important in many areas of science and engineering. In a wide range of applications, ranging from photonics and plasmonics to seismic exploration, efficient wave field solvers are required in various design and optimization frameworks. In this thesis, a Krylov subspace projection methodology is presented to efficiently solve wave propagation problems on unbounded domains. To model the extension of the computational domain to infinity, an optimal complex scaling method is introduced. Traditionally, complex scaling has been used to simulate open quantum systems. Here, an optimized complex scaling method is implemented that allows us to simulate wave propagation on unbounded domains provided we compute the propagating waves via a stability-corrected wave function. In our Krylov subspace framework, this wave function is approximated by polynomial or rational functions, which are obtained via Krylov subspace projection. We show that the field approximations are actually expansions in terms of approximate open resonance modes of the system and we present a novel and highly efficient Krylov subspace implementation for media exhibiting second-order relaxation effects. Numerical examples for one-, two-, and three-dimensional problems illustrate the performance of the method and show that our Krylov resonance expansions significantly outperform conventional solution methods.
Microelectronics, Circuits and Systems
Electrical Engineering
Electrical Engineering, Mathematics and Computer Science
Advisors/Committee Members: Remis, R.F. (mentor).
Subjects/Keywords: Computational Electromagnetics; Krylov subspace; model order reduction
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APA (6th Edition):
Zimmerling, J. T. (. (2014). Modeling of wave propagation in open domains: A Krylov subspace approach. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:aea44c4e-2658-474d-b9ea-c046066ac881
Chicago Manual of Style (16th Edition):
Zimmerling, J T (author). “Modeling of wave propagation in open domains: A Krylov subspace approach.” 2014. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:aea44c4e-2658-474d-b9ea-c046066ac881.
MLA Handbook (7th Edition):
Zimmerling, J T (author). “Modeling of wave propagation in open domains: A Krylov subspace approach.” 2014. Web. 07 Mar 2021.
Vancouver:
Zimmerling JT(. Modeling of wave propagation in open domains: A Krylov subspace approach. [Internet] [Masters thesis]. Delft University of Technology; 2014. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:aea44c4e-2658-474d-b9ea-c046066ac881.
Council of Science Editors:
Zimmerling JT(. Modeling of wave propagation in open domains: A Krylov subspace approach. [Masters Thesis]. Delft University of Technology; 2014. Available from: http://resolver.tudelft.nl/uuid:aea44c4e-2658-474d-b9ea-c046066ac881
Indian Institute of Science
5.
Milind, R.
Clustering for Model Reduction of Circuits : Multi-level Techniques.
Degree: MSc Engg, Faculty of Engineering, 2017, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/2774
► Miniaturisation of electronic chips poses challenges at the design stage. The progressively decreasing circuit dimensions result in complex electrical behaviour that necessitates complex models. Simulation…
(more)
▼ Miniaturisation of electronic chips poses challenges at the design stage. The
progressively decreasing circuit dimensions result in complex electrical behaviour
that necessitates complex models.
Simulation of complex circuit models involves extraordinarily large compu-
tational complexity. Such complexity is better managed through
Model Order
Reduction.
Model order reduction has been successful in large reductions in
system
order for most types of circuits, at high levels of accuracy. However,
multiport circuits with large number of inputs/outputs, pose an additional
computational challenge. A strategy based on
exible clustering of interconnects
results in more e cient
reduction of multiport circuits. Clustering methods
traditionally use Krylov-subspace methods such as PRIMA for the actual
model
reduction step. These clustering methods are unable to reduce the
model order to
the optimum extent. SVD-based methods like Truncated Balanced Realization
have shown higher
reduction potential than Krylov-subspace methods.
In this thesis, the di erences in
reduction potential and computational cost
thereof between SVD-based methods and Krylov-subspace methods are identi ed,
analyzed and quanti ed. A novel algorithm has been developed, utilizing a
particular combination of both these methods to achieve better results. It
enhances the clustering method for
model reduction using Truncated Balanced
Realization as a second-level
reduction technique. The algorithm is tested and
signi cant gains are illustrated. The proposed novel algorithm preserves the
other advantages of the current clustering algorithm.
Advisors/Committee Members: Raha, Soumyendu (advisor).
Subjects/Keywords: MOR; Model Order Reduction; Clustering based Model Reduction; Model Order Reduction Algorithms; PRIMA Clustering Model Reduction; Linear Circuits -; Electronic Circuits; Krylov-subspace Methods; Model Reduction; Electronic Engineering
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APA ·
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APA (6th Edition):
Milind, R. (2017). Clustering for Model Reduction of Circuits : Multi-level Techniques. (Masters Thesis). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/2774
Chicago Manual of Style (16th Edition):
Milind, R. “Clustering for Model Reduction of Circuits : Multi-level Techniques.” 2017. Masters Thesis, Indian Institute of Science. Accessed March 07, 2021.
http://etd.iisc.ac.in/handle/2005/2774.
MLA Handbook (7th Edition):
Milind, R. “Clustering for Model Reduction of Circuits : Multi-level Techniques.” 2017. Web. 07 Mar 2021.
Vancouver:
Milind R. Clustering for Model Reduction of Circuits : Multi-level Techniques. [Internet] [Masters thesis]. Indian Institute of Science; 2017. [cited 2021 Mar 07].
Available from: http://etd.iisc.ac.in/handle/2005/2774.
Council of Science Editors:
Milind R. Clustering for Model Reduction of Circuits : Multi-level Techniques. [Masters Thesis]. Indian Institute of Science; 2017. Available from: http://etd.iisc.ac.in/handle/2005/2774
Georgia Tech
6.
Issac, Yanal.
A quaternion approach to the modal analysis and reduced-order modeling of three-dimensional fluid systems.
Degree: PhD, Aerospace Engineering, 2020, Georgia Tech
URL: http://hdl.handle.net/1853/63702
► In 1967, Lumley derived the proper orthogonal decomposition (POD) in an attempt to provide a mathematical description of patterns that emerge in turbulent flow, which…
(more)
▼ In 1967, Lumley derived the proper orthogonal decomposition (POD) in an attempt to provide a mathematical description of patterns that emerge in turbulent flow, which he called coherent structures.
The POD method derived by Lumley has deep mathematical roots, is statistically based, and has analytical foundations that provide a rigorous mathematical framework for the extraction and description of coherent structures.
However, it was not until 1987, when Sirovich provided a numerically tractable implementation of the POD method capable of tackling large data sets such as the ones encountered in modern day engineering problems, did the POD gain much attention.
In recent years, the wide spread success of the POD method has greatly elevated the status of the POD method.
Today, the POD method is considered as benchmark procedure, and is at the bedrock of modal analysis and reduced-
order modeling of fluid systems.
Since its inception, numerous applications, adaptions and variations of the POD have been devised.
However, little attention has been paid to addressing the three-dimensional nature of fluid systems.
In fact, George states that the POD is agnostic to the nature of the data, as it does not matter whether the data is velocity, pressure or temperature.
The aim of this thesis was to explore a fundamentally different approach to the POD that is better suited for three-dimensional fluid systems; an approach that does not compromise the mathematical rigor associated with the concept of coherent structures defined by Lumley.
The approach investigated in this thesis replaces the traditional field of real numbers \R, with a four-dimensional non-commutative division algebra ℍ, known as the quaternion division algebra.
To the knowledge of the author, this thesis is the first to incorporate quaternions into Lumley's mathematical framework.
The introduction of quaternions into Lumley's mathematical framework, generalizes the proper orthogonal decomposition to the quaternion proper orthogonal decomposition (QPOD) while preserving its favorable features and extending the POD to higher dimensional spaces.
In the work of this thesis it was shown that a quaternion approach abstracts Lumley's mathematical representation of coherent structures at a fundamental level.
These abstracted representations, defined for the first time in the work of this thesis are termed quaternion coherent structures, exhibit interesting properties and result in a fascinating phenomena termed the kaleidoscope effect which is not present in the traditional definition of coherent structures.
Furthermore, it was numerically and mathematical shown that the QPOD method can better distill the essential dynamics present in a data set and can create more accurate rank-m approximations as compared the POD method.
The results presented in this thesis provide compelling evidence advocating for the use of quaternions in the context of modal analysis and reduced-
order modeling of three-dimensional fluid systems.
In addition a…
Advisors/Committee Members: Mavris, Dimitri (advisor), Silva, Walter (committee member), Eppink, Jenna (committee member), Sankar, Lakshmi (committee member), Pinon-Fischer, Olivia (committee member).
Subjects/Keywords: Reduced-order modeling; Model-order reduction; Quaternion; Proper orthogonal decomposition
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APA (6th Edition):
Issac, Y. (2020). A quaternion approach to the modal analysis and reduced-order modeling of three-dimensional fluid systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/63702
Chicago Manual of Style (16th Edition):
Issac, Yanal. “A quaternion approach to the modal analysis and reduced-order modeling of three-dimensional fluid systems.” 2020. Doctoral Dissertation, Georgia Tech. Accessed March 07, 2021.
http://hdl.handle.net/1853/63702.
MLA Handbook (7th Edition):
Issac, Yanal. “A quaternion approach to the modal analysis and reduced-order modeling of three-dimensional fluid systems.” 2020. Web. 07 Mar 2021.
Vancouver:
Issac Y. A quaternion approach to the modal analysis and reduced-order modeling of three-dimensional fluid systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2020. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1853/63702.
Council of Science Editors:
Issac Y. A quaternion approach to the modal analysis and reduced-order modeling of three-dimensional fluid systems. [Doctoral Dissertation]. Georgia Tech; 2020. Available from: http://hdl.handle.net/1853/63702
Cornell University
7.
Dobbs, Justin.
Toward A Streamlined Software Tool Chain For Cyber-Physical Buildings.
Degree: PhD, Mechanical Engineering, 2015, Cornell University
URL: http://hdl.handle.net/1813/41112
► Heating, ventilation, and air conditioning (HVAC) systems account for more than half of commercial building energy usage. Unfortunately, bottlenecks in early-stage design, control system implementation,…
(more)
▼ Heating, ventilation, and air conditioning (HVAC) systems account for more than half of commercial building energy usage. Unfortunately, bottlenecks in early-stage design, control system implementation, and building operation hinder the realization of maximally efficient buildings. First, high-fidelity simulation-crucial to an iterative, performance-driven design process-is too slow to use early in design, producing volumes of data but offering little insight. Second, creating dynamical models and implementing advanced
model-based HVAC controllers are both labor-intensive jobs beyond the scope of most projects. Third, during operation, fixed occupancy schedules become outdated and undermine the energy savings of even the most advanced HVAC equipment. This work addresses these bottlenecks using a novel software platform that seamlessly translates the building information
model (BIM) to alternate forms to suit various stages of the design and operation life cycle. First, in early stage design, we improve the speed of high-fidelity simulation by using a resistor-capacitor network abstraction to inform the thermal zone layout, facilitating
model order reduction while retaining simulation accuracy. Second, during control system implementation, we use a Modelica abstraction to eliminate the tedious manual control-oriented
model creation process and greatly speed the implementation of
model predictive control (MPC). Third, in operation, we enable controllers to adapt to changing occupancy schedules using a self-tuning Markov
model abstraction. This three-pronged approach removes tedious, specialized manual work to empower designers, engineers, and building operators to create and operate smarter, more energy efficient commercial buildings.
Advisors/Committee Members: Hencey,Brandon M. (chair), Albonesi,David H. (committee member), Greenberg,Donald P (committee member).
Subjects/Keywords: model order reduction; model predictive control; Markov occupancy model
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APA (6th Edition):
Dobbs, J. (2015). Toward A Streamlined Software Tool Chain For Cyber-Physical Buildings. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/41112
Chicago Manual of Style (16th Edition):
Dobbs, Justin. “Toward A Streamlined Software Tool Chain For Cyber-Physical Buildings.” 2015. Doctoral Dissertation, Cornell University. Accessed March 07, 2021.
http://hdl.handle.net/1813/41112.
MLA Handbook (7th Edition):
Dobbs, Justin. “Toward A Streamlined Software Tool Chain For Cyber-Physical Buildings.” 2015. Web. 07 Mar 2021.
Vancouver:
Dobbs J. Toward A Streamlined Software Tool Chain For Cyber-Physical Buildings. [Internet] [Doctoral dissertation]. Cornell University; 2015. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1813/41112.
Council of Science Editors:
Dobbs J. Toward A Streamlined Software Tool Chain For Cyber-Physical Buildings. [Doctoral Dissertation]. Cornell University; 2015. Available from: http://hdl.handle.net/1813/41112
Delft University of Technology
8.
van den Bosch, Valentijn (author).
Dynamic Substructuring for Efficient Vibrational Studies in Buildings.
Degree: 2019, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:c7d935ad-7276-4206-9ec3-df911936742e
► As a reaction to urban densication, light weight building is an attractive concept for optimally utilizing the capacity of the existing built environment. A common…
(more)
▼ As a reaction to urban densication, light weight building is an attractive concept for optimally utilizing the capacity of the existing built environment. A common issue paired with light weight construction is the need to engage in vibrational design, in
order to minimize hindrance due to human activities such as walking, that cause vibrations in buildings. The Finite Element Method (FEM) is a crucial tool for accurately predicting structural behaviour in such a context. The typical problem with FEM considering large, complex or detailed structures, is that analyses may demand intolerably large computational eort to perform design studies. As a solution, a component-wise approach called Component Mode Synthesis (CMS) is proposed. CMS technique involves separating a construction into substructures, after which
Model Order Reduction (MOR) is performed on each substructure individually. With this, the substructures are eciently described by a limited amount of Degrees of Freedom (DoF), after which they are assembled by means of Dynamic Substructuring (DS) techniques. Considering the large amounts of substructure DoF to be coupled to other assembly parts (typically containing 1%-10% of the total amount), an additional measure is required for analyses to be viable: a reliable interface
reduction should be performed to deal with the number of unreduced interface DoF that still exist. This research investigates interface
reduction by means of Orthogonal Polynomial Series, creating an a priori determined, generic
reduction basis which closely resembles the true vibration modes along substructure interfaces. Its performance is investigated with several conceptual case studies, conducting reduced
order analysis in Matlab and comparing the results with a full
order solution. Alterations are explored, including dierent polynomial bases (Legendre and Fourier), exible couplings and viscoelasticity at either coupled substructure boundaries or bodies. The relevance of complex modes in viscoelastic structures with lightly varying damping and stiness is examined, as well as accuracy of approximations of complex modes, with the prospect of enabling arbitrary frequency dependent material properties to be represented in an ecient manner. This involves approximation of complex modes, obtained by superposition of undamped modes, for which a strategy is developed to optimize considered inclusion of undamped modes. Ultimately, a representative building is modelled in
order to relate test results of OPS interface
reduction to an applicable context, and to prove the overall eectiveness of the enhanced CMS strategy for large light weight building models. OPS interface
reduction using Legendre series has shown to be a reliable and ecient technique depending on the frequency range considered. Its general error trends are mostly insignicant or manageable and exible/ viscoelastic boundary couplings do not de ate this. Disproportional viscoelasticity in substructure bodies, with respect to their mass and stiness matrices, are not necessarily…
Advisors/Committee Members: Metrikine, Andrei (graduation committee), van Dalen, Karel (graduation committee), de Klerk, Dennis (graduation committee), van der Seijs, Maarten (mentor), Hermens, Maurice (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: Dynamic Substructuring; Component Mode Synthesis; Model Order Reduction; Interface Reduction; Finite Element Method; Vibrations
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APA (6th Edition):
van den Bosch, V. (. (2019). Dynamic Substructuring for Efficient Vibrational Studies in Buildings. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:c7d935ad-7276-4206-9ec3-df911936742e
Chicago Manual of Style (16th Edition):
van den Bosch, Valentijn (author). “Dynamic Substructuring for Efficient Vibrational Studies in Buildings.” 2019. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:c7d935ad-7276-4206-9ec3-df911936742e.
MLA Handbook (7th Edition):
van den Bosch, Valentijn (author). “Dynamic Substructuring for Efficient Vibrational Studies in Buildings.” 2019. Web. 07 Mar 2021.
Vancouver:
van den Bosch V(. Dynamic Substructuring for Efficient Vibrational Studies in Buildings. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:c7d935ad-7276-4206-9ec3-df911936742e.
Council of Science Editors:
van den Bosch V(. Dynamic Substructuring for Efficient Vibrational Studies in Buildings. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:c7d935ad-7276-4206-9ec3-df911936742e
University of Michigan
9.
Choroszucha, Richard.
Control and Estimation Oriented Model Order Reduction for Linear and Nonlinear Systems.
Degree: PhD, Naval Architecture & Marine Engineering, 2017, University of Michigan
URL: http://hdl.handle.net/2027.42/140839
► Optimization based controls are advantageous in meeting stringent performance requirements and accommodating constraints. Although computers are becoming more powerful, solving optimization problems in real-time remains…
(more)
▼ Optimization based controls are advantageous in meeting stringent performance requirements and accommodating constraints. Although computers are becoming more powerful, solving optimization problems in real-time remains an obstacle because of associated computational complexity. Research efforts to address real-time optimization with limited computational power have intensified over the last decade, and one direction that has shown some success is
model order reduction.
This dissertation contains a collection of results relating to open- and closed-loop
reduction techniques for large scale unconstrained linear descriptor systems, constrained linear systems, and nonlinear systems.
For unconstrained linear descriptor systems, this dissertation develops novel gramian and Riccati solution approximation techniques. The gramian approximation is used for an open-loop
reduction technique following that of balanced truncation proposed by (Moore, 1981) for ordinary linear systems and (Stykel, 2004) for linear descriptor systems. The Riccati solution is used to generalize the Linear Quadratic Gaussian balanced truncation (LQGBT) of (Verriest, 1981) and (Jonckheere and Silverman, 1983). These are applied to an electric machine
model to reduce the number of states from >100000 to 8 while improving accuracy over the state-of-the-art modal truncation of (Zhou, 2015) for the purpose of condition monitoring. Furthermore, a link between unconstrained
model predictive control (MPC) with a terminal penalty and LQG of a linear system is noted, suggesting an LQGBT reduced
model as a natural
model for reduced MPC design. The efficacy of such a reduced controller is demonstrated by the real-time control of a diesel airpath.
Model reduction generally introduces modeling errors, and controlling a constrained plant
subject to modeling errors falls squarely into robust control. A standard assumption of robust control is that inputs/states/outputs are constrained by convex sets, and these sets are ``tightened'' for robust constraint satisfaction. However, robust control is often overly conservative, and resulting control strategies cannot take advantage of the true admissible sets. A new
reduction problem is proposed that considers the reduced
order model accuracy and constraint conservativeness. A constant tube methodology for reduced
order constrained MPC is presented, and the proposed reduced
order model is found to decrease the constraint conservativeness of the reduced
order MPC law compared to reduced
order models obtained by gramian and LQG reductions.
For nonlinear systems, a reformulation of the empirical gramians of (Lall et al., 1999) and (Hahn et al., 2003) into simpler, yet more general forms is provided. The modified definitions are used in the balanced truncation of a nonlinear diesel airpath
model, and the reduced
order model is used to design a reduced MPC law for tracking control. Further exploiting the link between the gramian and Riccati solution for linear systems, the new empirical gramian formulation is…
Advisors/Committee Members: Sun, Jing (committee member), Kolmanovsky, Ilya Vladimir (committee member), Butts, Kenneth Roy (committee member), Eustice, Ryan M (committee member).
Subjects/Keywords: Model Order Reduction; Naval Architecture and Marine Engineering; Engineering
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APA (6th Edition):
Choroszucha, R. (2017). Control and Estimation Oriented Model Order Reduction for Linear and Nonlinear Systems. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/140839
Chicago Manual of Style (16th Edition):
Choroszucha, Richard. “Control and Estimation Oriented Model Order Reduction for Linear and Nonlinear Systems.” 2017. Doctoral Dissertation, University of Michigan. Accessed March 07, 2021.
http://hdl.handle.net/2027.42/140839.
MLA Handbook (7th Edition):
Choroszucha, Richard. “Control and Estimation Oriented Model Order Reduction for Linear and Nonlinear Systems.” 2017. Web. 07 Mar 2021.
Vancouver:
Choroszucha R. Control and Estimation Oriented Model Order Reduction for Linear and Nonlinear Systems. [Internet] [Doctoral dissertation]. University of Michigan; 2017. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2027.42/140839.
Council of Science Editors:
Choroszucha R. Control and Estimation Oriented Model Order Reduction for Linear and Nonlinear Systems. [Doctoral Dissertation]. University of Michigan; 2017. Available from: http://hdl.handle.net/2027.42/140839
University of Toronto
10.
Yassine, Abdul-Amir.
A Fast Layer Elimination Approach for Power Grid Reduction in Integrated Circuits.
Degree: 2016, University of Toronto
URL: http://hdl.handle.net/1807/76134
► Simulation and verification of the on-die power delivery network (PDN) is one of the key steps in the design of integrated circuits. With the very…
(more)
▼ Simulation and verification of the on-die power delivery network (PDN) is one of the key steps in the design of integrated circuits. With the very large sizes of modern grids, verification of PDNs has become very expensive and a host of techniques for grid model approximation have been proposed. These include topological node elimination and full-blown numerical model order reduction (MOR). However, both of these traditional approaches suffer from drawbacks that limit their scalability to very large grids. In this thesis, we propose a novel technique for grid reduction that is a hybrid of both approaches  – the method is numerical but also factors in grid topology. It works by eliminating whole internal layers of the grid at a time, while aiming to preserve the dynamic behavior of the grid. Effectively, instead of traditional node-by-node topological elimination we provide a numerical layer-by-layer block-matrix approach that is both fast and accurate.
M.A.S.
Advisors/Committee Members: Najm, Farid N, Electrical and Computer Engineering.
Subjects/Keywords: Graph Sparsification; Integrated Circuits; Model Order Reduction; Power Grid; 0464
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APA (6th Edition):
Yassine, A. (2016). A Fast Layer Elimination Approach for Power Grid Reduction in Integrated Circuits. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/76134
Chicago Manual of Style (16th Edition):
Yassine, Abdul-Amir. “A Fast Layer Elimination Approach for Power Grid Reduction in Integrated Circuits.” 2016. Masters Thesis, University of Toronto. Accessed March 07, 2021.
http://hdl.handle.net/1807/76134.
MLA Handbook (7th Edition):
Yassine, Abdul-Amir. “A Fast Layer Elimination Approach for Power Grid Reduction in Integrated Circuits.” 2016. Web. 07 Mar 2021.
Vancouver:
Yassine A. A Fast Layer Elimination Approach for Power Grid Reduction in Integrated Circuits. [Internet] [Masters thesis]. University of Toronto; 2016. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1807/76134.
Council of Science Editors:
Yassine A. A Fast Layer Elimination Approach for Power Grid Reduction in Integrated Circuits. [Masters Thesis]. University of Toronto; 2016. Available from: http://hdl.handle.net/1807/76134
University of Toronto
11.
Yassine, Abdul-Amir.
A Fast Metal Layer Elimination Approach for Power Grid Reduction in Integrated Circuits.
Degree: 2016, University of Toronto
URL: http://hdl.handle.net/1807/76202
► Simulation and verification of the on-die power delivery network (PDN) is one of the key steps in the design of integrated circuits. With the very…
(more)
▼ Simulation and verification of the on-die power delivery network (PDN) is one of the key steps in the design of integrated circuits. With the very large sizes of modern grids, verification of PDNs has become very expensive and a host of techniques for grid model approximation have been proposed. These include topological node elimination and full-blown numerical model order reduction (MOR). However, both of these traditional approaches suffer from drawbacks that limit their scalability to very large grids. In this thesis, we propose a novel technique for grid reduction that is a hybrid of both approaches  – the method is numerical but also factors in grid topology. It works by eliminating whole internal layers of the grid at a time, while aiming to preserve the dynamic behavior of the grid. Effectively, instead of traditional node-by-node topological elimination we provide a numerical layer-by-layer block-matrix approach that is both fast and accurate.
M.A.S.
Advisors/Committee Members: Najm, Farid N, Electrical and Computer Engineering.
Subjects/Keywords: Graph Sparsification; Integrated Circuits; Model Order Reduction; Power Grid; 0464
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APA ·
Chicago ·
MLA ·
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APA (6th Edition):
Yassine, A. (2016). A Fast Metal Layer Elimination Approach for Power Grid Reduction in Integrated Circuits. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/76202
Chicago Manual of Style (16th Edition):
Yassine, Abdul-Amir. “A Fast Metal Layer Elimination Approach for Power Grid Reduction in Integrated Circuits.” 2016. Masters Thesis, University of Toronto. Accessed March 07, 2021.
http://hdl.handle.net/1807/76202.
MLA Handbook (7th Edition):
Yassine, Abdul-Amir. “A Fast Metal Layer Elimination Approach for Power Grid Reduction in Integrated Circuits.” 2016. Web. 07 Mar 2021.
Vancouver:
Yassine A. A Fast Metal Layer Elimination Approach for Power Grid Reduction in Integrated Circuits. [Internet] [Masters thesis]. University of Toronto; 2016. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1807/76202.
Council of Science Editors:
Yassine A. A Fast Metal Layer Elimination Approach for Power Grid Reduction in Integrated Circuits. [Masters Thesis]. University of Toronto; 2016. Available from: http://hdl.handle.net/1807/76202
University of Toronto
12.
Goyal, Ankit.
On-chip Power Grid Verification with Reduced Order Modeling.
Degree: 2010, University of Toronto
URL: http://hdl.handle.net/1807/25602
► To ensure the robustness of an integrated circuit design, its power distribution network (PDN) must be validated beforehand against any voltage drop on VDD nets.…
(more)
▼ To ensure the robustness of an integrated circuit design, its power distribution network (PDN) must be validated beforehand against any voltage drop on VDD nets. However, due to the increasing size of PDNs, it is becoming difficult to verify them in a reasonable amount of time. Lately, much work has been done to develop Model Order Reduction (MOR) techniques to reduce the size of power grids but their focus is more on simulation. In verification, we are concerned about the safety of nodes, including the ones which have been eliminated in the reduction process. This work proposes a novel approach to systematically reduce the power grid and accurately compute an upper bound on the voltage drops at power grid nodes which are retained. Furthermore, a criterion for the safety of nodes which are removed is established based on the safety of other nearby nodes and a user specified margin.
MAST
Advisors/Committee Members: Najm, Farid N., Electrical and Computer Engineering.
Subjects/Keywords: Power Grid Integrity Analysis; Model Order Reduction; 0544
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APA (6th Edition):
Goyal, A. (2010). On-chip Power Grid Verification with Reduced Order Modeling. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/25602
Chicago Manual of Style (16th Edition):
Goyal, Ankit. “On-chip Power Grid Verification with Reduced Order Modeling.” 2010. Masters Thesis, University of Toronto. Accessed March 07, 2021.
http://hdl.handle.net/1807/25602.
MLA Handbook (7th Edition):
Goyal, Ankit. “On-chip Power Grid Verification with Reduced Order Modeling.” 2010. Web. 07 Mar 2021.
Vancouver:
Goyal A. On-chip Power Grid Verification with Reduced Order Modeling. [Internet] [Masters thesis]. University of Toronto; 2010. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1807/25602.
Council of Science Editors:
Goyal A. On-chip Power Grid Verification with Reduced Order Modeling. [Masters Thesis]. University of Toronto; 2010. Available from: http://hdl.handle.net/1807/25602
Northeastern University
13.
Laxminarayan, Srinivas.
Low dimensional modeling of localized neural and hemodynamic response with habituation from multimodal brain measurements.
Degree: PhD, Department of Electrical and Computer Engineering, 2011, Northeastern University
URL: http://hdl.handle.net/2047/d20000954
► Multimodality functional brain imaging has been gaining importance due to the complementary nature of many of the modalities. Dynamical systems based models of neural activity…
(more)
▼ Multimodality functional brain imaging has been gaining importance due to the complementary nature of many of the modalities. Dynamical systems based models of neural activity and local hemodynamics can offer enhanced spatiotemporal resolution and insight into physiological signals and mechanisms. One major tool for studying brain function is to provoke local "evoked responses" by repeated application of a stimulus.; Evoked responses to stimuli show complex habituation behavior as the stimulus repetition frequency increases. To gain insight into the relation between local neural activity and hemodynamics we propose a control structure that enables neural mass models to predict habituation as revealed in rat EEG under medial nerve stimulus. We report on the accuracy with which these models recreate the data waveform under stimuli at varying frequencies (from 1-8 Hz), as well as the accuracy with which they mimic complete inhibition of firing at higher stimulus rates. We also compare the predictive power of the models, demonstrating the capability of simplified representations to capture key features of the mass evoked neuronal response.; Equipped with such a predictive neuronal model we explore the relationship between the neural response and the local hemodynamics by reconstructing the inputs of a Windkessel-based hemodynamic model and relating the basis functions of the neural signal to those of the inputs to the hemodynamic model. The model that relates the neuronal responses to the hemodynamic inputs is termed as the Neurovascular model.
Subjects/Keywords: habituation; low dimensional modeling; model order reduction; Engineering
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APA (6th Edition):
Laxminarayan, S. (2011). Low dimensional modeling of localized neural and hemodynamic response with habituation from multimodal brain measurements. (Doctoral Dissertation). Northeastern University. Retrieved from http://hdl.handle.net/2047/d20000954
Chicago Manual of Style (16th Edition):
Laxminarayan, Srinivas. “Low dimensional modeling of localized neural and hemodynamic response with habituation from multimodal brain measurements.” 2011. Doctoral Dissertation, Northeastern University. Accessed March 07, 2021.
http://hdl.handle.net/2047/d20000954.
MLA Handbook (7th Edition):
Laxminarayan, Srinivas. “Low dimensional modeling of localized neural and hemodynamic response with habituation from multimodal brain measurements.” 2011. Web. 07 Mar 2021.
Vancouver:
Laxminarayan S. Low dimensional modeling of localized neural and hemodynamic response with habituation from multimodal brain measurements. [Internet] [Doctoral dissertation]. Northeastern University; 2011. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2047/d20000954.
Council of Science Editors:
Laxminarayan S. Low dimensional modeling of localized neural and hemodynamic response with habituation from multimodal brain measurements. [Doctoral Dissertation]. Northeastern University; 2011. Available from: http://hdl.handle.net/2047/d20000954
Delft University of Technology
14.
Jain, S. (author).
Model Order Reduction for Non-Linear Structural Dynamics.
Degree: 2015, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:cb1d7058-2cfa-439a-bb2f-22a6b0e5bb2a
Engineering Mechanics
Precision and Microsystems Engineering
Mechanical, Maritime and Materials Engineering
Advisors/Committee Members: Van Gijzen, M.B. (mentor), Tiso, P. (mentor).Subjects/Keywords: Model Order Reduction; Nonlinear Manifold; Projection based MOR
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APA (6th Edition):
Jain, S. (. (2015). Model Order Reduction for Non-Linear Structural Dynamics. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:cb1d7058-2cfa-439a-bb2f-22a6b0e5bb2a
Chicago Manual of Style (16th Edition):
Jain, S (author). “Model Order Reduction for Non-Linear Structural Dynamics.” 2015. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:cb1d7058-2cfa-439a-bb2f-22a6b0e5bb2a.
MLA Handbook (7th Edition):
Jain, S (author). “Model Order Reduction for Non-Linear Structural Dynamics.” 2015. Web. 07 Mar 2021.
Vancouver:
Jain S(. Model Order Reduction for Non-Linear Structural Dynamics. [Internet] [Masters thesis]. Delft University of Technology; 2015. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:cb1d7058-2cfa-439a-bb2f-22a6b0e5bb2a.
Council of Science Editors:
Jain S(. Model Order Reduction for Non-Linear Structural Dynamics. [Masters Thesis]. Delft University of Technology; 2015. Available from: http://resolver.tudelft.nl/uuid:cb1d7058-2cfa-439a-bb2f-22a6b0e5bb2a
Delft University of Technology
15.
Zoutendijk, Mike (author).
Applying Deflation Methods in a Topology Optimization Procedure.
Degree: 2019, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:c5b85fd2-4745-465b-8988-6d9d59664343
► Structure Optimization has been an important subject with many applications for centuries. In the last sixty years, numerical optimization has facilitated large advancements in this…
(more)
▼ Structure Optimization has been an important subject with many applications for centuries. In the last sixty years, numerical optimization has facilitated large advancements in this field. One of the areas in Structure Optimization is Topology Optimization, which is used for Additive Manufacturing purposes. In this thesis we explore Static and Dynamic Topology Optimization. In the optimization problems matrix equations of the type Ax = b, with A sparse and badly conditioned, are accelerated using deflation techniques in addition to preconditioning. We have applied several iterative methods, preconditioners, and deflation types to the topology optimization problems. The static problem concerns compliance optimization of a two-dimensional MBB-beam. The deflation type that reduced the number of iterations the most without introducing large overhead costs was rigid body modes deflation, divided over element squares. It was found that dividing the rigid body modes vectors over density based regions did not reduce the number of iterations. The dynamic problem concerns eigenvalue optimization of a three-dimensional moving wafer stage that is used for laser-printing computer chips. The optimization formulation contains a shifted eigenvalue problem that is solved using model order reduction. In the computations of bases for the reduction matrix equations appear, to which deflation techniques were applied. All deflation types reduced the number of iterations and needed time to solve the matrix equations. The best deflation type was using rigid body modes (RBM) divided over element cubes combined with eigenvectors from the previous iteration. The next best was the same combination without the division over cubes. Using eigenvectors or RBM separately were the least effective deflation types. There is an optimal amount of element cubes to use when dividing the RBM. The tests on a few grid sizes suggested a quadrupling of the amount when the grid size doubles, but more research is needed to really identify a relation between the grid size and optimal amount. When increasing the grid size to a level where parallel computing on a cluster was required, the deflation type using element cubes could not be used due to complications with parallel implementation. Using the deflation type RBM and eigenvectors, reductions by a factor of 1.60 and 1.75 in the total needed time for 150 optimization iterations were achieved for grid sizes 120x120x20 and 180x180x30, respectively. In the first case the objective function of the optimized design converged further in the same amount of iterations when using deflation. future research could include using the promising deflation type RBM in cubes + eigenvectors in parallel computing to obtain an even larger time reduction in the optimization of the wafer stage with large grid sizes.
Applied Mathematics
Advisors/Committee Members: van Gijzen, Martin (mentor), Astudillo Rengifo, Reinaldo (mentor), Langelaar, Matthijs (graduation committee), van Horssen, Wim (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: Deflation; Topology Optimization; Model Order Reduction; Iterative methods; Wafer stage; PETSc
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APA (6th Edition):
Zoutendijk, M. (. (2019). Applying Deflation Methods in a Topology Optimization Procedure. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:c5b85fd2-4745-465b-8988-6d9d59664343
Chicago Manual of Style (16th Edition):
Zoutendijk, Mike (author). “Applying Deflation Methods in a Topology Optimization Procedure.” 2019. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:c5b85fd2-4745-465b-8988-6d9d59664343.
MLA Handbook (7th Edition):
Zoutendijk, Mike (author). “Applying Deflation Methods in a Topology Optimization Procedure.” 2019. Web. 07 Mar 2021.
Vancouver:
Zoutendijk M(. Applying Deflation Methods in a Topology Optimization Procedure. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:c5b85fd2-4745-465b-8988-6d9d59664343.
Council of Science Editors:
Zoutendijk M(. Applying Deflation Methods in a Topology Optimization Procedure. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:c5b85fd2-4745-465b-8988-6d9d59664343
Delft University of Technology
16.
Sombroek, C.S.M. (author).
Bridging the Gap Between Nonlinear Normal Modes and Modal Derivatives.
Degree: 2015, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:dc31561d-5fdc-47b4-bdcb-0957360bbed1
► Nonlinear Normal Modes (NNMs) have a clear conceptual relation to the classical linear normal modes (LNMs), yet they offer a solid theoretical framework for interpreting…
(more)
▼ Nonlinear Normal Modes (NNMs) have a clear conceptual relation to the classical linear normal modes (LNMs), yet they offer a solid theoretical framework for interpreting a wide class of non-linear dynamical phenomena with no linear counterpart. The main difficulty associating with NNMs is that the computation for real-size models is expensive, particularly for models with distributed nonlinearities e.g. those of geometric nature. The NNM computation involves repeated direct nonlinear time integration combined with a sensitivity analysis to determine the frequency-energy dependency for the modes of interest. In this thesis, NNMs are computed from reduced order models (ROMs) comprising LNMs and Modal Derivatives (MDs). The MDs have a direct relationship with the vibration modes (VMs), and can therefore be used as natural extension to LNMs to accurately represent the NNMs of interest. Two projection based reduction methods are used, one being the classical Galerkin projection reduction technique, the other is obtained from a quadratic coordinate transformation based on the Taylor series expansion. The NNMs computed from the ROMs are directly compared to those obtained from the full system analysis, which will highlight the importance of MDs in capturing essential nonlinear phenomena. The methodology is demonstrated on a doubly clamped beam, a shallow arch and a Roorda-frame.
Engineering Mechanics
Precision and Microsystems Engineering
Mechanical, Maritime and Materials Engineering
Advisors/Committee Members: Tiso, P. (mentor).
Subjects/Keywords: Nonlinear Normal Modes; Modal Derivatives; Model-order reduction; Quadratic manifold
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APA (6th Edition):
Sombroek, C. S. M. (. (2015). Bridging the Gap Between Nonlinear Normal Modes and Modal Derivatives. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:dc31561d-5fdc-47b4-bdcb-0957360bbed1
Chicago Manual of Style (16th Edition):
Sombroek, C S M (author). “Bridging the Gap Between Nonlinear Normal Modes and Modal Derivatives.” 2015. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:dc31561d-5fdc-47b4-bdcb-0957360bbed1.
MLA Handbook (7th Edition):
Sombroek, C S M (author). “Bridging the Gap Between Nonlinear Normal Modes and Modal Derivatives.” 2015. Web. 07 Mar 2021.
Vancouver:
Sombroek CSM(. Bridging the Gap Between Nonlinear Normal Modes and Modal Derivatives. [Internet] [Masters thesis]. Delft University of Technology; 2015. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:dc31561d-5fdc-47b4-bdcb-0957360bbed1.
Council of Science Editors:
Sombroek CSM(. Bridging the Gap Between Nonlinear Normal Modes and Modal Derivatives. [Masters Thesis]. Delft University of Technology; 2015. Available from: http://resolver.tudelft.nl/uuid:dc31561d-5fdc-47b4-bdcb-0957360bbed1
University of Illinois – Urbana-Champaign
17.
Nair, Nirmal Jayaprasad.
Transported snapshot model order reduction approach for parametric, steady-state fluid flows containing parameter dependent shocks.
Degree: MS, Aerospace Engineering, 2018, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/101093
► In this thesis, a new model order reduction approach is proposed for parametric steady-state nonlinear fluid flows characterized by shocks and discontinuities whose spatial locations…
(more)
▼ In this thesis, a new
model order reduction approach is proposed for parametric steady-state nonlinear fluid flows characterized by shocks and discontinuities whose spatial locations and orientations are strongly parameter dependent. In this method, solutions in the predictive regime are approximated using a linear superposition of parameter-dependent basis. The sought after parametric reduced-basis arise from solutions of linear transport equations. Key to the proposed approach is the observation that the optimal transport velocities are typically smooth and continuous, despite the solution themselves not being so. As a result, the transport fields can be accurately expressed using a low-
order polynomial expansion. Similar to traditional projection-based
model order reduction approaches, the proposed method is formulated mathematically as a residual minimization problem for the generalized coordinates. The method is successfully applied to the
reduction of a parametric 1-D flow in a converging-diverging nozzle, a parametric 2-D supersonic flow over a forward facing step and a parametric 2-D jet diffusion flame in a combustor.
Advisors/Committee Members: Balajewicz, Maciej (advisor).
Subjects/Keywords: parametric model order reduction; steady state residual; shock; hyperbolic PDE
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APA (6th Edition):
Nair, N. J. (2018). Transported snapshot model order reduction approach for parametric, steady-state fluid flows containing parameter dependent shocks. (Thesis). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/101093
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nair, Nirmal Jayaprasad. “Transported snapshot model order reduction approach for parametric, steady-state fluid flows containing parameter dependent shocks.” 2018. Thesis, University of Illinois – Urbana-Champaign. Accessed March 07, 2021.
http://hdl.handle.net/2142/101093.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nair, Nirmal Jayaprasad. “Transported snapshot model order reduction approach for parametric, steady-state fluid flows containing parameter dependent shocks.” 2018. Web. 07 Mar 2021.
Vancouver:
Nair NJ. Transported snapshot model order reduction approach for parametric, steady-state fluid flows containing parameter dependent shocks. [Internet] [Thesis]. University of Illinois – Urbana-Champaign; 2018. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2142/101093.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nair NJ. Transported snapshot model order reduction approach for parametric, steady-state fluid flows containing parameter dependent shocks. [Thesis]. University of Illinois – Urbana-Champaign; 2018. Available from: http://hdl.handle.net/2142/101093
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
18.
Mangat, Naunidh (author).
Reduced order wind turbine aeroelastic modelling for condition monitoring & fault detection.
Degree: 2019, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:69a1c261-39ad-4b6b-b280-715f1fe94a1e
► Wind energy has emerged as a promising alternative to fossil fuel energy sources over the last two decades partly due to considerable reductions in the…
(more)
▼ Wind energy has emerged as a promising alternative to fossil fuel energy sources over the last two decades partly due to considerable reductions in the cost of power production. A common trend towards cost
reduction has been to build larger and lighter wind turbines. These produce more power per unit and use less material. Another strategy for cost
reduction could be to reduce the Operations & Maintenance (O&M) costs of wind turbines by using optimal O&M strategies. O&M costs account for approximately one-fourth of the overall energy cost for the full lifetime of a wind turbine. They assume even greater significance in the wake of growing interest in offshore wind farms since offshore wind turbines operate in harsher environments compared to their onshore counterparts and are more difficult to access. Condition monitoring has been proposed as a novel preventive maintenance strategy wherein sensors are employed to collect data related to the functioning of an operational wind turbine. This data can be processed to get meaningful information about component health of the wind turbine. An aeroelastic
model can be used to simulate the fault-free response of the wind turbine for given operating conditions. By comparing real-time information from the condition monitoring system and aeroelastic
model, it may be possible to develop routines which can detect developing faults in the wind turbine components. This forms the basis of a
model-based condition monitoring system (MOD-CMS). For purposes of
model-based condition monitoring it is required to have an aeroelastic
model which is computationally fast to be capable of running real-time aeroelastic load simulations, and is highly accurate in
order to detect faults. Furthermore, it is also desirable to have a linear aeroelastic
model since this can also be used for controller and state observer design. A state observer can help estimate states of the wind turbine which are not easily measurable. This thesis reviews state-of-the-art aeroelastic tools to get a better understanding of their limitations. A reduced-
order aeroelastic
model is developed using the aeroelastic module in STAS WPP (State Space Analysis of Wind Power Plants) which is an open-source aero-hydro-servo-elastic tool in the Matlab/Octave environment. The linear reduced
order aeroelastic
model is verified by running test cases in the frequency domain for the NREL 5MW Baseline wind turbine. The accuracy of the linearized
model is demonstrated by performing a stability analysis study for the NREL 5MW Baseline wind turbine. Furthermore, different coupling and numerical integration schemes are studied to develop a time marching simulation tool. Two main approaches are proposed. The first involves time marching of the monolithic, strongly coupled non-linear aeroelastic
model using a multistep predictor-corrector integration scheme. In the second approach, a partitioned, loosely coupled version of the linear aeroelastic
model is implicitly integrated over time. In the present work a tool based on…
Advisors/Committee Members: Holierhoek, Jessica (mentor), Meng, Fanzhong (mentor), Watson, Simon (graduation committee), van Zuijlen, Alexander (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: Aeroelasticity; Reduced order model; Wind Energy; Structural Dynamics; Condition Monitoring; Fault Detection; aeroelastic instabilities; model order reduction
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APA (6th Edition):
Mangat, N. (. (2019). Reduced order wind turbine aeroelastic modelling for condition monitoring & fault detection. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:69a1c261-39ad-4b6b-b280-715f1fe94a1e
Chicago Manual of Style (16th Edition):
Mangat, Naunidh (author). “Reduced order wind turbine aeroelastic modelling for condition monitoring & fault detection.” 2019. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:69a1c261-39ad-4b6b-b280-715f1fe94a1e.
MLA Handbook (7th Edition):
Mangat, Naunidh (author). “Reduced order wind turbine aeroelastic modelling for condition monitoring & fault detection.” 2019. Web. 07 Mar 2021.
Vancouver:
Mangat N(. Reduced order wind turbine aeroelastic modelling for condition monitoring & fault detection. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:69a1c261-39ad-4b6b-b280-715f1fe94a1e.
Council of Science Editors:
Mangat N(. Reduced order wind turbine aeroelastic modelling for condition monitoring & fault detection. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:69a1c261-39ad-4b6b-b280-715f1fe94a1e
University of Waterloo
19.
Nguyen, Khanh V. Q.
Model Reduction for Vehicle Systems Modelling.
Degree: 2014, University of Waterloo
URL: http://hdl.handle.net/10012/8395
► The full model of a double-wishbone suspension has more than 30 differential-algebraic equations which takes a remarkably long time to simulate. By contrast, the look-up…
(more)
▼ The full model of a double-wishbone suspension has more than 30 differential-algebraic equations which takes a remarkably long time to simulate. By contrast, the look-up table for the same suspension is simulated much faster, but may not be very accurate. Therefore, developing reduced models that approximate complex systems is necessary because model reduction decreases the simulation time in comparison with the original model, enables real time applications, and produces acceptable accuracy.
In this research, we focus on model reduction techniques for vehicle systems such as suspensions and how they are approximated by models having lower degrees of freedom. First, some existing model reduction techniques, such as irreducible realization procedures, balanced truncation, and activity-based reduction, are implemented to some vehicle suspensions. Based on the application of these techniques, their disadvantages are revealed. Then, two methods of model reduction for multi-body systems are proposed.
The first proposed method is 2-norm power-based model reduction (2NPR) that combines 2-norm of power and genetic algorithms to derive reduced models having lower degrees of freedom and fewer number of components. In the 2NPR, some components such as mass, damper, and spring are removed from the original system. Afterward, the values of the remaining components are adjusted by the genetic algorithms. The most important advantage of the 2NPR is keeping the topology of multi-body systems which is useful for design purposes.
The second method uses proper orthogonal decomposition. First, the equations of motion for a multi-body system are converted to explicit second-order differential equations. Second, the projection matrix is obtained from simulation or experimental data by proper orthogonal decomposition. Finally, the equations of motion are transferred to a lower-dimensional state coordinate system.
The implementation of the 2NPR to two double-wishbone suspensions and the comparison with other techniques such as balanced truncation and activity-based model reduction also demonstrate the efficiency of the new reduction technique.
Subjects/Keywords: model reduction; model order reduction; truncation; proper orthogonal decomposition; genetic algorithm; vehicle; suspension; multibody system; MapleSim; Maple
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APA (6th Edition):
Nguyen, K. V. Q. (2014). Model Reduction for Vehicle Systems Modelling. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/8395
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nguyen, Khanh V Q. “Model Reduction for Vehicle Systems Modelling.” 2014. Thesis, University of Waterloo. Accessed March 07, 2021.
http://hdl.handle.net/10012/8395.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nguyen, Khanh V Q. “Model Reduction for Vehicle Systems Modelling.” 2014. Web. 07 Mar 2021.
Vancouver:
Nguyen KVQ. Model Reduction for Vehicle Systems Modelling. [Internet] [Thesis]. University of Waterloo; 2014. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10012/8395.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nguyen KVQ. Model Reduction for Vehicle Systems Modelling. [Thesis]. University of Waterloo; 2014. Available from: http://hdl.handle.net/10012/8395
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Ottawa
20.
Baggu, Gnanesh.
Efficient Approach for Order Selection of Projection-Based Model Order Reduction
.
Degree: 2018, University of Ottawa
URL: http://hdl.handle.net/10393/37967
► The present thrust in the electronics industry towards integrating multiple functions on a single chip while operating at very high frequencies has highlighted the need…
(more)
▼ The present thrust in the electronics industry towards integrating multiple functions on a single chip while operating at very high frequencies has highlighted the need for efficient Electronic Design Automation (EDA) tools to shorten the design cycle and capture market windows. However, the increasing complexity in modern circuit design has made simulation a computationally cumbersome task. The notion of model order reduction has emerged as an effective tool to address this difficulty. Typically, there are numerous approaches and several issues involved in the implementation of model-order reduction techniques. Among the important ones of those issues is the problem of determining a suitable order (or size) for the reduced system. An optimal order would be the minimal order that enables the reduced system to capture the
behavior of the original (more complex and larger) system up to a user-defined frequency. The contribution presented in this thesis describes a new approach aimed at determining the order of the reduced system. The proposed approach is based on approximating the impulse response of the original system in the time-domain. The core methodology in obtaining that approximation is based on numerically inverting the Laplace-domain of the representation of the impulse response from the complex-domain (s-domain) into the time-domain. The main advantage of the proposed approach is that it allows the order selection algorithm to operate directly on the time-domain form of the impulse response. It is well-known that numerically generating the impulse response in the time-domain is very difficult and its not impossible, since it requires driving the original network with the Dirac-delta function, which is a mathematical abstraction rather than a concrete waveform that can be implemented on a digital computer. However, such a difficulty is avoided in the proposed approach since it uses the Laplace-domain image of the impulse response to obtain its time-domain representation. The numerical simulations presented in the thesis demonstrate that using the time-domain waveform of the impulse response, computed using the proposed approach and properly filtered with a Butterworth filter, guides the order selection algorithm to select a smaller order, i.e., the reduced system becomes more compact in size. The phrase "smaller or more compact" in this context refers to the comparison with existing techniques currently in use, which seek to generate some form of time-domain approximations for the impulse response through driving the original network with pulse-shaped function (e.g., Gaussian pulse).
Subjects/Keywords: Model Order Reduction;
Projection-based techniques;
Order Selection;
False Nearest Neighbors;
Numerical Inversion of Lapalce Transform;
Impulse response;
Butterworth filter
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APA (6th Edition):
Baggu, G. (2018). Efficient Approach for Order Selection of Projection-Based Model Order Reduction
. (Thesis). University of Ottawa. Retrieved from http://hdl.handle.net/10393/37967
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Baggu, Gnanesh. “Efficient Approach for Order Selection of Projection-Based Model Order Reduction
.” 2018. Thesis, University of Ottawa. Accessed March 07, 2021.
http://hdl.handle.net/10393/37967.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Baggu, Gnanesh. “Efficient Approach for Order Selection of Projection-Based Model Order Reduction
.” 2018. Web. 07 Mar 2021.
Vancouver:
Baggu G. Efficient Approach for Order Selection of Projection-Based Model Order Reduction
. [Internet] [Thesis]. University of Ottawa; 2018. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10393/37967.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Baggu G. Efficient Approach for Order Selection of Projection-Based Model Order Reduction
. [Thesis]. University of Ottawa; 2018. Available from: http://hdl.handle.net/10393/37967
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Utah
21.
Kordy, Michal Adam.
Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics.
Degree: PhD, Mathematics, 2014, University of Utah
URL: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3313/rec/835
► The motivation for this work is the forward and inverse problem for magnetotellurics, a frequency domain electromagnetic remote-sensing geophysical method used in mineral, geothermal, and…
(more)
▼ The motivation for this work is the forward and inverse problem for magnetotellurics, a frequency domain electromagnetic remote-sensing geophysical method used in mineral, geothermal, and groundwater exploration. The dissertation consists of four papers. In the first paper, we prove the existence and uniqueness of a representation of any vector field in H(curl) by a vector lying in H(curl) and H(div). It allows us to represent electric or magnetic fields by another vector field, for which nodal finite element approximation may be used in the case of non-constant electromagneticproperties. With this approach, the system matrix does not become ill-posed for lowfrequency In the second paper, we consider hexahedral finite element approximation of an electric field for the magnetotelluric forward problem. The near-null space of the system matrix for low frequencies makes the numerical solution unstable in the air. We show that the proper solution may obtained by applying a correction on the nullspace of the curl. It is done by solving a Poisson equation using discrete Helmholtz decomposition. We parallelize the forward code on multicore workstation with large RAM. In the next paper, we use the forward code in the inversion. Regularization of the inversion is done by using the second norm of the logarithm of conductivity.The data space Gauss-Newton approach allows for significant savings in memory and computational time. We show the efficiency of the method by considering a numberof synthetic inversions and we apply it to real data collected in Cascade Mountains.The last paper considers a cross-frequency interpolation of the forward response as well as the Jacobian. We consider Pade approximation through model order reduction and rational Krylov subspace. The interpolating frequencies are chosen adaptively in order to minimize the maximum error of interpolation. Two error indicator functions are compared. We prove a theorem of almost always lucky failure in the case of the right hand analytically dependent on frequency. The operator's null space is treated by decomposing the solution into the part in the null space and orthogonal to it.
Subjects/Keywords: Finite element method; Inverse problem; Magnetotellurics; Maxwell's equations; Model order reduction; Rational krylov subspaces
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APA (6th Edition):
Kordy, M. A. (2014). Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics. (Doctoral Dissertation). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3313/rec/835
Chicago Manual of Style (16th Edition):
Kordy, Michal Adam. “Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics.” 2014. Doctoral Dissertation, University of Utah. Accessed March 07, 2021.
http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3313/rec/835.
MLA Handbook (7th Edition):
Kordy, Michal Adam. “Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics.” 2014. Web. 07 Mar 2021.
Vancouver:
Kordy MA. Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics. [Internet] [Doctoral dissertation]. University of Utah; 2014. [cited 2021 Mar 07].
Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3313/rec/835.
Council of Science Editors:
Kordy MA. Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics. [Doctoral Dissertation]. University of Utah; 2014. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3313/rec/835
University of Toronto
22.
Li, Xihao.
Model Order Reduction and Stability Enforcement of Finite-difference Time-domain Equations Beyond the CFL Limit.
Degree: 2014, University of Toronto
URL: http://hdl.handle.net/1807/74637
► The Finite-Difference Time Domain (FDTD) method is a versatile and popular method for solving Maxwell's equations. As a consequence of the explicit time integration, the…
(more)
▼ The Finite-Difference Time Domain (FDTD) method is a versatile and popular method for solving Maxwell's equations. As a consequence of the explicit time integration, the maximum stable time-step of FDTD is constrained by the Courant-Friedrichs-Lewy (CFL) limit. This thesis focuses on two interdependent topics: model order reduction (MOR) of explicit FDTD equations and stability enforcement above the CFL limit. The combination of these two topics leads to the proposed CFL extension technique which has been demonstrated for 2D and 3D simulations. In addition, the proposed method has also been applied to the FDTD sub-gridding application. Comparisons have been made with existing implicit and explicit CFL extension techniques with respect to versatility, computational efficiency, and numerical dispersion errors. While there exist computation and memory limitations, the proposed method has demonstrated excellent versatility and accuracy for all test cases while having significant speed-ups over standard FDTD.
M.A.S.
2016-11-19 00:00:00
Advisors/Committee Members: Triverio, Piero, Sarris, Costas D, Electrical and Computer Engineering.
Subjects/Keywords: CFL Extension; FDTD Sub-gridding; Finite-Difference Time Domain; Model Order Reduction; Stability Enforcement; 0607
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APA ·
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APA (6th Edition):
Li, X. (2014). Model Order Reduction and Stability Enforcement of Finite-difference Time-domain Equations Beyond the CFL Limit. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/74637
Chicago Manual of Style (16th Edition):
Li, Xihao. “Model Order Reduction and Stability Enforcement of Finite-difference Time-domain Equations Beyond the CFL Limit.” 2014. Masters Thesis, University of Toronto. Accessed March 07, 2021.
http://hdl.handle.net/1807/74637.
MLA Handbook (7th Edition):
Li, Xihao. “Model Order Reduction and Stability Enforcement of Finite-difference Time-domain Equations Beyond the CFL Limit.” 2014. Web. 07 Mar 2021.
Vancouver:
Li X. Model Order Reduction and Stability Enforcement of Finite-difference Time-domain Equations Beyond the CFL Limit. [Internet] [Masters thesis]. University of Toronto; 2014. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1807/74637.
Council of Science Editors:
Li X. Model Order Reduction and Stability Enforcement of Finite-difference Time-domain Equations Beyond the CFL Limit. [Masters Thesis]. University of Toronto; 2014. Available from: http://hdl.handle.net/1807/74637
23.
和田, 雅之.
Model Order Reductionを用ã„ãŸãƒªã‚¢ãƒ«ã‚¿ã‚¤ãƒ 大変形シミュレーション(è¦æ—¨).
Degree: 修士(環境å¦), 2017, The University of Tokyo / æ±äº¬å¤§å¦
URL: http://hdl.handle.net/2261/52336
► Recently the demand of real-time physics base simulation has been rising in the CG animation area. It is popular to use spring-damper model or Finite…
(more)
▼ Recently the demand of real-time physics base simulation has been rising in the CG animation area. It is popular to use spring-damper model or Finite Element Method, but these have either low accuracy or high cost. In this report, we propose a new method of real-time large deformation simulation by Model Order Reduction. Our method is derived by linear eigenvalue equations or Krylov subspace. The new method gives good approximation of nonlinear FEM and reduces the time cost drastically both static analyses and dynamic analyses.
Subjects/Keywords: Model Order Reduction; リアルタイム; 大変形; FEM; Real-time; Finite Element Method; Large deformation
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APA (6th Edition):
和田, é. (2017). Model Order Reductionを用ã„ãŸãƒªã‚¢ãƒ«ã‚¿ã‚¤ãƒ 大変形シミュレーション(è¦æ—¨). (Thesis). The University of Tokyo / æ±äº¬å¤§å¦. Retrieved from http://hdl.handle.net/2261/52336
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
和田, 雅之. “Model Order Reductionを用ã„ãŸãƒªã‚¢ãƒ«ã‚¿ã‚¤ãƒ 大変形シミュレーション(è¦æ—¨).” 2017. Thesis, The University of Tokyo / æ±äº¬å¤§å¦. Accessed March 07, 2021.
http://hdl.handle.net/2261/52336.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
和田, 雅之. “Model Order Reductionを用ã„ãŸãƒªã‚¢ãƒ«ã‚¿ã‚¤ãƒ 大変形シミュレーション(è¦æ—¨).” 2017. Web. 07 Mar 2021.
Vancouver:
和田 é. Model Order Reductionを用ã„ãŸãƒªã‚¢ãƒ«ã‚¿ã‚¤ãƒ 大変形シミュレーション(è¦æ—¨). [Internet] [Thesis]. The University of Tokyo / æ±äº¬å¤§å¦; 2017. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2261/52336.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
和田 é. Model Order Reductionを用ã„ãŸãƒªã‚¢ãƒ«ã‚¿ã‚¤ãƒ 大変形シミュレーション(è¦æ—¨). [Thesis]. The University of Tokyo / æ±äº¬å¤§å¦; 2017. Available from: http://hdl.handle.net/2261/52336
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
24.
Otaño Aramendi, Nerea.
Réduction du coût de calcul pour la simulation du comportement mécanique de câbles : Reduction of the computational cost for the numerical simulation of the mehcanical behaviour of wire ropes.
Degree: Docteur es, Mécanique des solides, 2016, Université Paris-Saclay (ComUE)
URL: http://www.theses.fr/2016SACLC061
► Le travail présenté dans ce mémoire s'intéresse à la simulation du comportement mécanique de câbles d'ascenseurs. Le but de ce travail est d'élaborer une méthode…
(more)
▼ Le travail présenté dans ce mémoire s'intéresse à la simulation du comportement mécanique de câbles d'ascenseurs. Le but de ce travail est d'élaborer une méthode permettant de simuler le comportement mécanique de tels câbles à moindre coût, et avec une précision suffisante.Dans un premier temps, différentes méthodes permettant de modéliser ou de simuler le comportement de ces câbles ont été comparées, et leurs avantages et inconvénients ont été analysés. Les résultats de modèles analytiques et de simulations éléments finis ont été comparés avec des données expérimentales. Les modèles analytiques considérés dans ce travail présentent un coût de calcul bien moins élevé que les modèles éléments finis, mais n'offrent pas une précision suffisante dans leurs résultats pour simuler le comportement de câbles d'ascenseurs. L'approche éléments finis a été retenue pour cette raison comme la plus adaptée pour simuler ce genre de câbles. Les coûts de calcul liés à cette approche sont cependant très élevés, et demandent la mise en oeuvre de méthodes particulières en vue de les réduire.Afin de réduire les temps de calculs, trois types de méthodes ont été considérées : les méthodes d'homogénéisation, les méta-modèles, et les techniques de réduction de modèle. L'approche de réduction de modèle a été retenue comme la plus appropriée et a été implémentée dans le code de simulation par éléments finis Multifil. Des résultats avec une bonne précision ont été obtenus en utilisant cette méthode, mais les coûts des simulations initiales sur le modèle complet afin d'obtenir un ensemble de solutions permettant de construire une base réduite apparaissent trop élevés dès qu'il s'agit de traiter des câbles de longueurs importantes. Pour remédier à ce problème, une méthode de réduction par tronçon a été formulée et implémentée. Cette méthode tire parti de la structure périodique du câble et permet d'identifier a base de réduction seulement sur un motif périodique élémentaire. Cette base est ensuite utilisée pour représenter la solution sur l'ensemble d'un câble composé de plusieurs tronçons.Le coût des multiplications matricielles nécessaires pour transformer le système linéaire du problème initial, en système linéaire réduit reste cependant trop important pour obtenir un gain significatif, en particulier dans le contexte de la résolution d'un problème non-linéaire. Pour pallier cette difficulté, une technique supplémentaire, appelée ``Discrete Empirical Interpolation Method'' (DEIM), a été mise en oeuvre avec succès, et a permis d'obtenir au final une réduction du coût de calcul d'un facteur 4.
The work presented in this dissertation is focused on the simulation of the mechanical behaviour of lift's wire ropes. The aim of the work is to elaborate a method to simulate the mechanical behaviour of such wire ropes with low computational cost and sufficient accuracy.First of all, several methods to model or simulate wire ropes have been compared and their weak and strong points have been highlighted. Analytical and finite element methods have been…
Advisors/Committee Members: Ben Dhia, Hachmi (thesis director), Durville, Damien (thesis director).
Subjects/Keywords: Modèle ordre réduction; Simulation numérique; Metamodèles; Câble; Model order reduction; Numerical simulation; Metamodels; Wire rope
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APA ·
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MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Otaño Aramendi, N. (2016). Réduction du coût de calcul pour la simulation du comportement mécanique de câbles : Reduction of the computational cost for the numerical simulation of the mehcanical behaviour of wire ropes. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2016SACLC061
Chicago Manual of Style (16th Edition):
Otaño Aramendi, Nerea. “Réduction du coût de calcul pour la simulation du comportement mécanique de câbles : Reduction of the computational cost for the numerical simulation of the mehcanical behaviour of wire ropes.” 2016. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed March 07, 2021.
http://www.theses.fr/2016SACLC061.
MLA Handbook (7th Edition):
Otaño Aramendi, Nerea. “Réduction du coût de calcul pour la simulation du comportement mécanique de câbles : Reduction of the computational cost for the numerical simulation of the mehcanical behaviour of wire ropes.” 2016. Web. 07 Mar 2021.
Vancouver:
Otaño Aramendi N. Réduction du coût de calcul pour la simulation du comportement mécanique de câbles : Reduction of the computational cost for the numerical simulation of the mehcanical behaviour of wire ropes. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016SACLC061.
Council of Science Editors:
Otaño Aramendi N. Réduction du coût de calcul pour la simulation du comportement mécanique de câbles : Reduction of the computational cost for the numerical simulation of the mehcanical behaviour of wire ropes. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2016. Available from: http://www.theses.fr/2016SACLC061
Delft University of Technology
25.
Van der Linde, T.M. (author).
Fast topology optimization for transient mechanical problems.
Degree: 2016, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:2aa17c56-66a2-41c8-95fc-a1af50dc52dd
► Topology optimization is increasingly used as a design tool in engineering. Within structural mechanics, most applications focus on statics. An extension to time-domain (transient) dynamics…
(more)
▼ Topology optimization is increasingly used as a design tool in engineering. Within structural mechanics, most applications focus on statics. An extension to time-domain (transient) dynamics will have many useful applications, but this is currently hindered by high computational costs. The goal of this research is to reduce these costs by applying model order reduction. In model order reduction, the full coordinates of a system are approximated by a much smaller number of reduced coordinates and associated basis vectors. A few options for these vectors will be discussed. It is shown that using load-based methods results in high accuracy, especially the Ritz vector method. In the total optimization this leads to significant reduction of both CPU-time and memory requirements.
Engineering Mechanics
Precision and Microsystems Engineering
Mechanical, Maritime and Materials Engineering
Advisors/Committee Members: Langelaar, M. (mentor).
Subjects/Keywords: topology optimization; time-domain dynamics; transient dynamics; model order reduction; Ritz vectors
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APA (6th Edition):
Van der Linde, T. M. (. (2016). Fast topology optimization for transient mechanical problems. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:2aa17c56-66a2-41c8-95fc-a1af50dc52dd
Chicago Manual of Style (16th Edition):
Van der Linde, T M (author). “Fast topology optimization for transient mechanical problems.” 2016. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:2aa17c56-66a2-41c8-95fc-a1af50dc52dd.
MLA Handbook (7th Edition):
Van der Linde, T M (author). “Fast topology optimization for transient mechanical problems.” 2016. Web. 07 Mar 2021.
Vancouver:
Van der Linde TM(. Fast topology optimization for transient mechanical problems. [Internet] [Masters thesis]. Delft University of Technology; 2016. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:2aa17c56-66a2-41c8-95fc-a1af50dc52dd.
Council of Science Editors:
Van der Linde TM(. Fast topology optimization for transient mechanical problems. [Masters Thesis]. Delft University of Technology; 2016. Available from: http://resolver.tudelft.nl/uuid:2aa17c56-66a2-41c8-95fc-a1af50dc52dd
Delft University of Technology
26.
Jagt, Declan (author).
Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation.
Degree: 2020, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:b20d6d07-a071-4bff-8e55-9f434f09650c
► Although a transition to more sustainable energy production is necessary, fossil fuels will remain a crucial contributor to the world's energy production in the near…
(more)
▼ Although a transition to more sustainable energy production is necessary, fossil fuels will remain a crucial contributor to the world's energy production in the near future. In numerically maximizing the production of these fuels, as well as in many other optimization problems, an objective function has to be optimized on the basis of an input vector, related through some underlying model. Although the adjoint methodology generally allows for efficient gradient-based optimization of such a problem, it quickly becomes infeasible when the model comprises a large-scale system, or access to this model is prohibited. To resolve this, we consider the application of a model order reduction scheme, in combination with subdomain surrogate modeling, to perform the optimization using a reduced-order approximation of the model. In particular, we employ principal orthogonal decomposition (POD), efficiently reducing the size of the underlying system of equations, on the basis of a limited number of samples of the full-order model. Applying a domain decomposition, this number of samples can be reduced even further, although at a decreased efficiency. Next, radial basis function (RBF) interpolation is applied, using the samples to construct a trajectory piecewise linear approximation of the reduced-order model in each subdomain. Combining these different techniques, an optimization algorithm is constructed, applying the adjoint methodology to the reduced-order model in order to compute an approximate gradient. The accuracy of this approximation was found to be poor, but comparable to alternative sample-based methods. An improved accuracy could be achieved by reducing the number of input parameters, allowing for more efficient optimization when applying the algorithm to a particular reservoir model. For another model, however, the algorithm performed worse upon reducing the size of the input, as a result of the fewer degrees of freedom in the optimization procedure. Reacquiring this freedom during the optimization, improved results could be attained, but the number of iterations and thus the cost of the method increased drastically. Comparing the full input implementation to another sample-based method, specifically a straight gradient ensemble algorithm, it was found to produce comparable results. Each method was able to surpass the other, dependent on the particular situation, though the reduced-adjoint algorithm generally expended more effort to attain similar results. This suggests that further study is necessary, for example improving the RBF interpolation or input reduction techniques, to fully exploit the benefits of the POD-TPWL methodology.
Applied Mathematics
Advisors/Committee Members: Heemink, Arnold (mentor), van der Woude, Jacob (graduation committee), Leeuwenburgh, Olwijn (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: Production optimization; Adjoint-based optimization; Model-order reduction; Surrogate modelling; Reservoir simulation
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APA ·
Chicago ·
MLA ·
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CSE |
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jagt, D. (. (2020). Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:b20d6d07-a071-4bff-8e55-9f434f09650c
Chicago Manual of Style (16th Edition):
Jagt, Declan (author). “Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation.” 2020. Masters Thesis, Delft University of Technology. Accessed March 07, 2021.
http://resolver.tudelft.nl/uuid:b20d6d07-a071-4bff-8e55-9f434f09650c.
MLA Handbook (7th Edition):
Jagt, Declan (author). “Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation.” 2020. Web. 07 Mar 2021.
Vancouver:
Jagt D(. Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Mar 07].
Available from: http://resolver.tudelft.nl/uuid:b20d6d07-a071-4bff-8e55-9f434f09650c.
Council of Science Editors:
Jagt D(. Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:b20d6d07-a071-4bff-8e55-9f434f09650c
Princeton University
27.
Zhang, Hao.
Data-driven Modeling for Fluid Dynamics and Control
.
Degree: PhD, 2020, Princeton University
URL: http://arks.princeton.edu/ark:/88435/dsp0108612r49q
► One of the most critical tasks in fluid dynamics and control is to build simple, low-order, and accurate models. The models are essential for understanding…
(more)
▼ One of the most critical tasks in fluid dynamics and control is to build simple, low-
order, and accurate models. The models are essential for understanding dynamics and control. However, in many cases, the models are either unknown or too complicated to be useful. As an example, fluid flows are governed by Navier-Stokes equations (NSE), which remain intractable for real-time applications. Meanwhile, with increasing computational power and advances in experimental and numerical methods, researchers have access to much more data about dynamical systems. For instance, computational fluid dynamics (CFD) produces tons of data, but the data have not been fully utilized.
Data-driven modeling addresses these challenges by learning dynamical system models from data. This thesis focuses on data-driven modeling methods for applications in fluid dynamics and control. First, we propose an evaluation criterion to quantify the accuracy of dynamic mode decomposition (DMD), a data-driven algorithm for extracting spatial and temporal features about dynamical systems from data. DMD is a numerical approximation to the linear Koopman operator associated with a dynamical system. By exploiting this connection, the accuracy criterion is purely data-driven and physically meaningful. It also applies to other variants of DMD algorithms and assists in
model selection.
Second, fast algorithms are developed for online dynamic mode decomposition (ODMD). Given real-time measurement about a dynamical system, this algorithm efficiently updates an adaptive
model upon each new snapshot. It reduces both the computational time and memory requirements by
order of magnitudes compared with existing methods. ODMD algorithm can be modified to gradually forget old data, which enables faster tracking of dynamics. ODMD also extends to both linear and nonlinear system identification, where control is included.
Finally, we study the input-output response of a separated flow past a flat plate. The analysis is based on the frequency-domain transfer function of the linearized NSE about the mean flow. The control input is body forcing, and the output is the flow field. This analysis sheds light on the optimal control placement and reveals that the trailing edge separation bubble is most sensitive to streamwise body force (control) in upstream of the separation point.
Advisors/Committee Members: Rowley, Clarence W (advisor).
Subjects/Keywords: Control;
Data-driven modeling;
Dynamical systems;
Fluid dynamics;
Model reduction;
Reduced-order modeling
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APA (6th Edition):
Zhang, H. (2020). Data-driven Modeling for Fluid Dynamics and Control
. (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp0108612r49q
Chicago Manual of Style (16th Edition):
Zhang, Hao. “Data-driven Modeling for Fluid Dynamics and Control
.” 2020. Doctoral Dissertation, Princeton University. Accessed March 07, 2021.
http://arks.princeton.edu/ark:/88435/dsp0108612r49q.
MLA Handbook (7th Edition):
Zhang, Hao. “Data-driven Modeling for Fluid Dynamics and Control
.” 2020. Web. 07 Mar 2021.
Vancouver:
Zhang H. Data-driven Modeling for Fluid Dynamics and Control
. [Internet] [Doctoral dissertation]. Princeton University; 2020. [cited 2021 Mar 07].
Available from: http://arks.princeton.edu/ark:/88435/dsp0108612r49q.
Council of Science Editors:
Zhang H. Data-driven Modeling for Fluid Dynamics and Control
. [Doctoral Dissertation]. Princeton University; 2020. Available from: http://arks.princeton.edu/ark:/88435/dsp0108612r49q
Duke University
28.
Balajewicz, Maciej.
A New Approach to Model Order Reduction of the Navier-Stokes Equations
.
Degree: 2012, Duke University
URL: http://hdl.handle.net/10161/5854
► A new method of stabilizing low-order, proper orthogonal decomposition based reduced-order models of the Navier Stokes equations is proposed. Unlike traditional approaches, this method…
(more)
▼ A new method of stabilizing low-
order, proper orthogonal decomposition based reduced-
order models of the Navier Stokes equations is proposed. Unlike traditional approaches, this method does not rely on empirical turbulence modeling or modification of the Navier-Stokes equations. It provides spatial basis functions different from the usual proper orthogonal decomposition basis function in that, in addition to optimally representing the solution, the new proposed basis functions also provide stable reduced-
order models. The proposed approach is illustrated with two test cases: two-dimensional flow inside a square lid-driven cavity and a two-dimensional mixing layer.
Advisors/Committee Members: Dowell, Earl H (advisor).
Subjects/Keywords: Engineering;
Aerospace engineering;
model reduction;
Navier-Stokes;
proper orthogonal decomposition;
reduced order modeling;
stabilization;
turbulence
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APA (6th Edition):
Balajewicz, M. (2012). A New Approach to Model Order Reduction of the Navier-Stokes Equations
. (Thesis). Duke University. Retrieved from http://hdl.handle.net/10161/5854
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Balajewicz, Maciej. “A New Approach to Model Order Reduction of the Navier-Stokes Equations
.” 2012. Thesis, Duke University. Accessed March 07, 2021.
http://hdl.handle.net/10161/5854.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Balajewicz, Maciej. “A New Approach to Model Order Reduction of the Navier-Stokes Equations
.” 2012. Web. 07 Mar 2021.
Vancouver:
Balajewicz M. A New Approach to Model Order Reduction of the Navier-Stokes Equations
. [Internet] [Thesis]. Duke University; 2012. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10161/5854.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Balajewicz M. A New Approach to Model Order Reduction of the Navier-Stokes Equations
. [Thesis]. Duke University; 2012. Available from: http://hdl.handle.net/10161/5854
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Loughborough University
29.
Bogdanski, Karol.
Reduced order modelling through system identification using stochastic filtering.
Degree: PhD, 2019, Loughborough University
URL: https://doi.org/10.26174/thesis.lboro.8216285.v1
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785294
► This thesis presents a novel approach to model order reduction, through system identification and using stochastic filtering. Order reduction is a particularly relevant application in…
(more)
▼ This thesis presents a novel approach to model order reduction, through system identification and using stochastic filtering. Order reduction is a particularly relevant application in the automotive context, as the generation of simplified simulation models for the whole vehicle and its subsystems is an increasingly important aspect of vehicle design. First, grey-box parameter identification of vehicle handling dynamics is explored, including identification of a combined-slip tyre model. This introductory study serves as an intermediate step to review three alternative stochastic filters: identifying forms of the unscented Kalman filter, extended Kalman filter and particle filter are here compared for effectiveness, complexity and computational efficiency. Despite being initially merely considered as a stepping stone towards black-box identification, this phase of the PhD generated its own and independent outcomes and might be viewed as a spin-off of the main research topic. All three filters appear suited to system identification and could operate in on-line model predictive controllers or estimators, with varying levels of practicability at different sampling rates. Work on black-box system identification then starts through a non-linear Kalman filter, extended to identify all the parameters of a canonical linear state-space structure. In spite of all model parameters being unknown at the start, the filter is able to evolve parameter estimates to achieve 100% accuracy in noise-free test cases, and is also proven to be robust to noise in the measurements. The canonical form ensures that a minimal number of parameters need to be identified and produces additional information in terms of eigenvalues and dominant modes. After extensive testing in the linear domain, state-space is extended into a non-linear framework, with each parameter becoming a non-linear function of system inputs or states. Parameter variation is first constrained by cubic spline polynomials, to provide continuity and maintain relatively small extended state-parameter vectors. This early approach is later simplified, with each element of state-space generated through unconstrained, generic non-linear functions and defined through a number of equally spaced, fixed nodes. Conditioning and convergence are maintained through the definition of additional system outputs, based on specific functions of the non-linear node ordinates. Unlike other methods published in the literature, this new approach does not focus on a specific non-linear structure, but consists in the prescription of a generic and yet simple non-linear state-space model structure, that allows various non-linearities to be identified and approximated solely based on inputs and outputs. The method is illustrated in practice through simple non-linear examples and test cases, which include the identification of a full vehicle model, a highly non-linear brake model and CFD data. These applications show that it is possible to easily expand the order of the system and the complexity of the…
Subjects/Keywords: Engineering not elsewhere classified; model order reduction; Kalman Filter; System identification; vehicle dynamics
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APA ·
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APA (6th Edition):
Bogdanski, K. (2019). Reduced order modelling through system identification using stochastic filtering. (Doctoral Dissertation). Loughborough University. Retrieved from https://doi.org/10.26174/thesis.lboro.8216285.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785294
Chicago Manual of Style (16th Edition):
Bogdanski, Karol. “Reduced order modelling through system identification using stochastic filtering.” 2019. Doctoral Dissertation, Loughborough University. Accessed March 07, 2021.
https://doi.org/10.26174/thesis.lboro.8216285.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785294.
MLA Handbook (7th Edition):
Bogdanski, Karol. “Reduced order modelling through system identification using stochastic filtering.” 2019. Web. 07 Mar 2021.
Vancouver:
Bogdanski K. Reduced order modelling through system identification using stochastic filtering. [Internet] [Doctoral dissertation]. Loughborough University; 2019. [cited 2021 Mar 07].
Available from: https://doi.org/10.26174/thesis.lboro.8216285.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785294.
Council of Science Editors:
Bogdanski K. Reduced order modelling through system identification using stochastic filtering. [Doctoral Dissertation]. Loughborough University; 2019. Available from: https://doi.org/10.26174/thesis.lboro.8216285.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785294
The Ohio State University
30.
Riddle, Derek S.
Model Order Reduction and Control of an Organic Rankine
Cycle Waste Heat Recovery System.
Degree: MS, Mechanical Engineering, 2017, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu150055199341535
► As fuel efficiency and emissions requirements continue to rise, auto manufacturers are continuously striving to adopt new technologies to help reach these goals. With methods…
(more)
▼ As fuel efficiency and emissions requirements continue
to rise, auto manufacturers are continuously striving to adopt new
technologies to help reach these goals. With methods such as
turbocharging, direct fuel injection, variable valve actuation, and
engine stop-start now common in mass production vehicles, the next
step forward could be in waste heat recovery. In most vehicles
today, more than 60 percent of fuel energy is lost to waste heat in
the cooling system and exhaust. The higher temperature heat energy
in the exhaust can be recovered using an Organic Rankine Cycle
(ORC). Past research on ORC's focused on creating highly detailed
models for performance prediction or controlling extremely simple
models. Neither of these options are ideal for use in operating a
real system. The detailed
model is too slow and the controls based
on the simple
model are not accurate enough to predict what the
real system will do. This thesis takes a highly detailed
model and
uses
model order reduction to create a reduced
order model which
retains most of the prediction accuracy of the full
model but is
now smaller and faster. This new reduced
model has been used with
feedforward and feedback controls, but it also has the potential to
be used in advanced
model based controls such as
model predictive
control (MPC).
Advisors/Committee Members: Canova, Marcello (Advisor).
Subjects/Keywords: Mechanical Engineering; ORC; waste heat recovery; model order reduction; thermal system modelling; simulation
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APA ·
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Manager
APA (6th Edition):
Riddle, D. S. (2017). Model Order Reduction and Control of an Organic Rankine
Cycle Waste Heat Recovery System. (Masters Thesis). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu150055199341535
Chicago Manual of Style (16th Edition):
Riddle, Derek S. “Model Order Reduction and Control of an Organic Rankine
Cycle Waste Heat Recovery System.” 2017. Masters Thesis, The Ohio State University. Accessed March 07, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu150055199341535.
MLA Handbook (7th Edition):
Riddle, Derek S. “Model Order Reduction and Control of an Organic Rankine
Cycle Waste Heat Recovery System.” 2017. Web. 07 Mar 2021.
Vancouver:
Riddle DS. Model Order Reduction and Control of an Organic Rankine
Cycle Waste Heat Recovery System. [Internet] [Masters thesis]. The Ohio State University; 2017. [cited 2021 Mar 07].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu150055199341535.
Council of Science Editors:
Riddle DS. Model Order Reduction and Control of an Organic Rankine
Cycle Waste Heat Recovery System. [Masters Thesis]. The Ohio State University; 2017. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu150055199341535
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Open Access Theses and Dissertations