Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 110 for “"reduced-order modeling"”.
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Approximate Deconvolution Reduced Order Modeling
This thesis proposes a large eddy simulation reduced order model (LES-ROM) framework for the numerical simulation of realistic flows. In this LES-ROM framework, the proper orthogonal decomposition (POD) is used to define the ROM basis and a POD differential filter is used to define the large ROM …
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Reduced-order modeling of aeroelastic phenomena
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-12-04 without embargo terms
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Reduced order modeling of distillation systems
… separation feasibility is investigated using reduced-order models. Three different models of nonequilibrium rate-based packed distillation columns are developed, each with progressive levels of complexity. The final model is the most complex, and is based on the Maxwell-Stefan theory of mass …
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Commutation Error in Reduced Order Modeling
… on the recently proposed data-driven correction reduced order model (DDC-ROM). We compare two filters: the ROM projection, which was originally used to develop the DDC-ROM, and the ROM differential filter, which uses a Helmholtz operator to attenuate the small scales in the input signal. We focus …
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Reduced Order Modeling of Flapping Wing Flight Dynamics
… forcing due to complex, unsteady aerodynamics. Reduced order models are critical to formulating tractable sensing and control concepts from the complex physics of flapping wing flight. Previous research has focused on a single methodology for the estimation of flight dynamics. This dissertation …
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Dynamic reduced order modeling of entrained flow gasifiers
… use of abundant and secure fossil fuels. Dynamic reduced order models (ROMs) that predict the operation of entrained flow gasifiers (EFGs) within IGCC (integrated gasification combined cycle) or polygeneration plants are essential for understanding the fundamental processes of importance. Such …
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Reduced-order modeling of power electronics components and systems
… the seemingly inevitable compromise between modeling fidelity and simulation speed in power electronics. Higher-order effects are considered at the component and system levels. Order-reduction techniques are applied to provide insight into accurate, computationally efficient component-level …
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Reduced-order modeling of MEMS using modal basis functions
… the development of computer-aided design and modeling tools (CAD/CAM) that enable designers to reduce the time and cost it takes to produce working prototypes. An ideal scenario is one in which a designer is able to quickly model and simulate an entire microsystem - sensors, actuators and …
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Adaptive Stochastic Reduced-Order Modeling for Autonomous Ocean Platforms
… for these platforms, efficient adaptive reduced-order models (ROMs) are needed. In this thesis, we first review existing approaches and then develop a new adaptive Dynamic Mode Decomposition (DMD)-based, data-driven, reduced-order model framework that provides onboard forecasting and data …
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Cross-Validation of Data-Driven Correction Reduced Order Modeling
… this thesis, we develop a data-driven correction reduced order model (DDC-ROM) for numerical simulation of fluid flows. The general DDC-ROM involves two stages: (1) we apply ROM filtering (such as ROM projection) to the full order model (FOM) and construct the filtered ROM (F-ROM). (2) We use …
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Non-linear reduced order modeling for transport dominated fuid systems
Reduced order modeling aims to approximate large and complex dynamical systems with smaller ones to reduce simulation costs in the design or control processes of these systems. Standard linear mode-based model order reduction (MOR) can fail for transport dominated fluid systems (TDFS), because the …
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Flow control and sensing using data-driven reduced-order modeling
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2022-04-06 without embargo terms
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IGFEM-based reduced-order modeling and design of nonlinear composites
… is the computational cost associated with modeling the mechanical behavior of complex domains as optimization algorithms are usually iterative, requiring many evaluations of the domain response. For this reason, the majority of existing work on this subject focuses on linear theory. In this …
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Physics-based machine learning and data-driven reduced-order modeling
This thesis considers the task of learning efficient low-dimensional models for dynamical systems. To be effective in an engineering setting, these models must be predictive -- that is, they must yield reliable predictions for conditions outside the data used to train them. These models must also …
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Reduced-order modeling for ensemble real-time estimation and control
… problems, this thesis proposes a robust reduced-order model for subsurface solute transport that is sufficiently accurate in the ensemble closed-loop process. The reduced-order model is based on a second-order expansion of the governing equations discretized by the mixed finite element …
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Biomass characterization and reduced order modeling of mixed-feedstock gasification
… of the art in biomass pyrolysis/devolatilization modeling. An existing coal Entrained Flow Gasification (EFG) Reduced Order Model (ROM) was expanded to more accurately simulate the gasification of a mixed feedstock of biomass and coal. The GE 2700tpd gasifier was used because it is a widely used …
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System Identification CFD-Based Reduced-Order Modeling for Hypersonic Vehicles
… (SID) techniques were utilized to assemble reduced-order models purposed for estimating the aerodynamic coefficients of a hypersonic vehicle subjected to flight conditions of interest. The reduced-order models combined the accuracy of high-fidelity hybrid Reynolds Averaged Navier-Stokes …
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High-order retractions for reduced-order modeling and uncertainty quantification
… problems grows just as fast. As a consequence, reduced-order modeling has become an essential technique in the computational scientist's toolbox. By reducing the dimensionality of a system, we are able to obtain approximate solutions to otherwise intractable problems. And because the methodology …
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Development of a reduced-order modeling technique for granular locomotion
… aimed towards the development and expansion of a reduced-order modeling technique called granular Resistive Force Theory(RFT) for modeling wheeled locomotion on granular beds. A combination of various modeling techniques, namely plasticity-based continuum modeling, discrete element method (DEM) …
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Reduced-order modeling of granular intrusions driven by continuum approaches
… metals) and fluids (like water). This makes modeling granular media challenging. While the field of granular physics extensively uses grain-scale Discrete Elements Modeling (DEM) to model such characteristics of granular systems, they are computationally expensive. On the other hand, …
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