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Showing 1 to 20 of 23 for “"Reduced Order Model (ROM)"”.
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Biomass characterization and reduced order modeling of mixed-feedstock gasification
There has been much effort to characterize and model coal for use in combustion and gasification. This work seeks to delineate the differences and similarities between biomass and coal, with emphasis on the state of the art in biomass pyrolysis/devolatilization modeling. An existing coal Entrained …
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Flight Dynamics and Maneuver Loads on a Commercial Aircraft with Discrete Source Damage
… can introduce asymmetries that complicate the modeling. An extended vortex lattice code is used to model the quasi-steady aerodynamic forces. The vortex lattice method provides the force distribution which is not available elsewhere. Snapshots from the vortex lattice model are used to generate …
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Efficient 𝐻₂-Based Parametric Model Reduction via Greedy Search
Dynamical systems are mathematical models of physical phenomena widely used throughout the world today. When a dynamical system is too large to effectively use, we turn to model reduction to obtain a smaller dynamical system that preserves the behavior of the original. In many cases these models …
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Comparative Evaluation of Vorticity Transport Modeled Distortions and High-Fidelity ANSYS Solutions Using Modal Assurance Criterion
… the evaluation of a vorticity transport based reduced order model (ROM) in comparison to similar data created through Ansys CFX simulation for three canonical swirl flow profiles: Bulk Swirl, Twin Swirl, and Quad Swirl. Modal decomposition through singular value decomposition (SVD) is performed …
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Optimal Dirichlet boundary control problems of high-lift configurations with control and integral state constraints
… noch auf einem k-omega-Wilcox98 Turbulenzmodell, welches zu einem riesigen Rechenaufwand führt. Zur Lösung dieses Problems diskutieren wir eine Modellreduktion und ein reduced-order model (ROM), indem wir ein kleines System von gewöhnlichen Differentialgleichungen mit Hilfe von vorher …
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Data-Driven Variational Multiscale Reduced Order Modeling of Turbulent Flows
… strategies for improving the projection-based reduced order model (ROM) accuracy: (I) adding closure terms to the standard ROM; (II) using Lagrangian data to improve the ROM basis. Following strategy (I), we propose a new data-driven reduced order model (ROM) framework that centers around the …
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DMD and POD Modal Analysis for Store Separation
<p>Store separation from aircraft and spacecraft has historically been a critical and in some cases fatal issue for the aerospace industry. Given the severity of the issue much effort has been spent on the development of processes to identify failure flight conditions for store separation. The …
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Model reduction for nonlinear dynamical systems with parametric uncertainties
… to input parameters. In this thesis, we apply model order reduction to an important class of such systems -- one which exhibits limit cycle oscillations (LCOs) and Hopf-bifurcations. Highfidelity simulations for systems with LCOs are computationally intensive, precluding probabilistic analyses …
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Control of flexible spacecraft during a minimum-time maneuver
… spacecraft regarded as rigid represents the zero-order problem and the control of elastic vibration, as well as of elastic perturbations from the rigid-body maneuver, represents the first-order problem. The zero-order control is to be carried out in minimum time, which implies on-off control. On …
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Combined Experimental and Numerical Study of Active Thermal Control of Battery Modules
… (Li-ion) batteries have been identified as a promising solution to meet the increasing demands for alternative energy in electric vehicles (EVs) and hybrid electric vehicle (HEVs). This work describes experimental and numerical study of thermal management of battery module consisting of …
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Real-time Autonomy and Maneuvering Simulation of an Unmanned Underwater Vehicle Near a Moving Submarine Using Actively Sampled Gaussian Process Surrogate Models
… simulators have severe limitations on modeling UUV motion near a moving submarine because they are not capable of determining the complex, turbulent, hydrodynamic interactions in real time. Potential flow solvers are typically fast enough, but they neglect viscosity which introduces …
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Robust Parameter Inversion Using Stochastic Estimates
… routine is a large burden. While techniques from model order reduction can partially alleviate the computational cost, obtaining error bounds in parameter space is typically not feasible. In this work, we examine two different remedies based on stochastic estimates of the objective function. …
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Fire Simulation Cost Reduction for Improved Safety and Response for Underground Spaces
… to reduce fire and airflow simulation costs in order to make simulation of complex systems around fire and mine ventilation systems viable. This study will examine the development of a Reduced Order Model (ROM) to predict the flow field of an underground mine geometry using proper orthogonal …
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Physics-informed neural surrogates for next-generation aerothermochemical modeling
… State-to-state (StS) collisional–radiative (CR) models provide the highest level of physical fidelity by explicitly resolving the species population dynamics of individual quantum energy levels of each species. However, the dimensionality of these models increases exponentially with the number of …
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Investigations on Vortex-induced Vibration (VIV) Phenomena of Single-and-double-cylinder Flexible Beam Arrangements of Energy Harvesters
… is still a feasible and economical method. Mix model coupling the acceleration, velocity and displacement model of structure acting on vortex shedding wake, is a possible way to extend their applicability to finite length cylinder harvester or higher amplitude oscillation. A good agreement with …
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Vortex-induced vibration of a linearly-sprung cylinder with nonlinear energy sinks
… efficient, one-way transfer of kinetic energy from the former to the latter, where it is dissipated through a process known as targeted energy transfer. We use a spectral-element approach to compute the flow and the rigid-body quantities, and show that for values of the Reynolds number in the …
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Adaptive Simulation Modelling Using The Digital Twin Paradigm
… throughout the struc- ture’s life cycle, from design to decommissioning. The main goal is to ensure that through an ongoing process of risk management, the structure’s continued fitness-for-purpose (FFP) is maintained – allowing for optimal use of the structure with a minimal chance of …
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Reduced-order modeling and adjoint-based optimization of flows with fluid-structure interactions
… (POD) and Galerkin projection based reduced-order model (ROM) has been developed to represent the essential physics of a FSI system with moving solid boundaries. The ROM is able to work on both numerical and experimental two-dimensional (2D) and three-dimensional (3D) dataset, and has …
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Dynamic mode decomposition with application to optimal control
… problems is especially cost prohibitive. In order to keep computational cost within a reasonable level, we explore the potential of merging data-driven model reduction with optimal control. In particular, we demonstrate the application of Dynamic Mode Decomposition (DMD) to the adjoint-based …
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Aeroelastic Analysis of Truss-Braced Wing Aircraft: Applications for Multidisciplinary Design Optimization
… were investigated. These TBW designs obtained from the MDO environment while minimizing fuel burn resemble a Boeing 777-200 Long Range (LR) aircraft both in terms of flight mission and aircraft configuration. The VGRWT can sweep forward and aft relative to the wing with the aid of a Novel …
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