Searched for: subject%3A%22Adaptive%255C+mesh%255C+refinement%22
(1 - 19 of 19)
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Li, X. (author)
This thesis contributes to the effective and efficient application of unsteady adjoint methods to Adaptive Mesh Refinement (AMR) for Large Eddy Simulation (LES). Three aspects, i.e., subgrid-scale model error, storage cost of high-dimensional data, and stability of the adjoint problem for turbulent flows, were studied to make adjoint-based mesh...
doctoral thesis 2023
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Schiller, Carl (author)
In Geodesy, the development of accurate Digital Elevation Models of the surface helps to provide height data for various applications in other Earth Science disciplines. These models are used as base models for studies. Geophysics can be a support science when providing base models for non-invasive studies inside the Earth. Such models can be...
master thesis 2023
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Halevy, Avi (author)
In this work residual error estimates are constructed using Neural Networks for Finite Element Method. These can be used to do adaptive mesh refinement. Two neural networks are developed the Multilayer Perceptron and the Transformer model. The error estimates are made for 1d poisson equations but the idea will generalise to higher dimensions as...
bachelor thesis 2022
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Hosseinimehr, S.M. (author)
In various geo-engineering fields, accurate and scalable modeling of fluid and heat transport in the subsurface fractured porous media is important in order to fulfill scientific, economical and societal expectations on successful field development plans. Such models and the predictions they provide, contribute to efficient and safe operations...
doctoral thesis 2021
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Li, X. (author), Hulshoff, S.J. (author), Hickel, S. (author)
Adaptive mesh refinement (AMR) is potentially an effective way to automatically generate computational meshes for high-fidelity simulations such as Large Eddy Simulation (LES). Adjoint methods, which are able to localize error contributions, can be used to optimize the mesh for computing a physical quantity of interest (e.g. lift, drag)...
journal article 2021
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de Hoop, S. (author), Jones, Elodie (author), Voskov, D.V. (author)
A coupled description of flow and thermal-reactive transport is spanning a wide range of scales in space and time, which often introduces a significant complexity for the modelling of such processes. Subsurface reservoir heterogeneity with complex multi-scale features increases the modelling complexity even further. Traditional multiscale...
journal article 2021
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Li, X. (author), Hulshoff, S.J. (author), Hickel, S. (author)
Adaptive Mesh Refinement (AMR) is potentially an effective way to automatically generate computational meshes for high-fidelity simulations such as Large Eddy Simulation (LES). When combined with adjoint methods, which are able to localize error contributions, AMR can generate meshes that are optimal for computing a physical quantity of...
journal article 2021
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Barfknecht, Nils (author)
Computational fluid dynamics (CFD) has become an indispensable tool in research and engineering. Even though the performance of computers is increasing at unfathomable speeds, the calculation of many fluid problems remains to be challenging. With the emerging widespread use of Large Eddy Simulation (LES), the computational cost of simulations...
master thesis 2020
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Hosseinimehr, S.M. (author), Vuik, Cornelis (author), Hajibeygi, H. (author)
An algebraic dynamic multilevel (ADM) method for fully-coupled simulation of flow and heat transport in heterogeneous fractured geothermal reservoirs is presented. Fractures are modeled explicitly using the projection-based embedded discrete method (pEDFM), which accurately represents fractures with generic conductivity values, from barriers to...
journal article 2020
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Hajibeygi, H. (author), Olivares, Manuela Bastidas (author), Hosseinimehr, S.M. (author), Pop, Sorin (author), Wheeler, Mary (author)
Accurate simulation of multiphase flow in subsurface formations is challenging, as the formations span large length scales (km) with high-resolution heterogeneous properties. To deal with this challenge, different multiscale methods have been developed. Such methods construct coarse-scale systems, based on a given high-resolution fine-scale...
journal article 2020
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Kunnen, Jeroen (author)
In 2011 a relatively new type of numerical scheme has been introduced: Active Flux schemes. In this type of scheme an extra degree of freedom is added to the cell interfaces of a regular finite volume grid. This enables the use of non-conservative update methods for these additional variables, as conservation is automatically adhered to by the...
master thesis 2018
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van Hooft, J.A. (author), Popinet, Stéphane (author), van Heerwaarden, Chiel C. (author), van der Linden, S.J.A. (author), de Roode, S.R. (author), van de Wiel, B.J.H. (author)
We present a proof-of-concept for the adaptive mesh refinement method applied to atmospheric boundary-layer simulations. Such a method may form an attractive alternative to static grids for studies on atmospheric flows that have a high degree of scale separation in space and/or time. Examples include the diurnal cycle and a convective...
journal article 2018
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Hosseinimehr, S.M. (author), Cusini, M. (author), Vuik, Cornelis (author), Hajibeygi, H. (author)
We present an algebraic dynamic multilevel method for multiphase flow in heterogeneous fractured porous media (F-ADM), where fractures are resolved at fine scale with an embedded discrete modelling approach. This fine-scale discrete system employs independent fine-scale computational grids for heterogeneous matrix and discrete fractures,...
journal article 2018
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Heaney, C.E. (author), Bonnier, P.G. (author), Brinkgreve, R.B.J. (author), Hicks, M.A. (author)
The implementation of Adaptive Mesh Refinement (AMR) within the geotechnical software package PLAXIS 2D is described in this paper. A recovery-based algorithm is used which aims to reduce the discretisation error by refining the mesh during the solution process. The error is estimated with a Zienkiewicz-Zhu-type error estimator but based on the...
conference paper 2013
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Kästner, K. (author)
This thesis is about the numerical approximation of the spectrum of the confined hydrogen atom. The energy levels and wave functions of the hydrogen atom are modelled by the corresponding eigenvalues and eigenvectors of the Schrödinger equation with Coulomb potential. At first different discretisation techniques for the hydrogenic Schrödinger...
master thesis 2012
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Van der Zee, K.G. (author), Van Brummelen, E.H. (author), De Borst, R. (author)
We develop duality-based a posteriori error estimates for functional outputs of solutions of free-boundary problems via shape-linearization principles. To derive an appropriate dual (linearized adjoint) problem, we linearize the domain dependence of the very weak form and goal functional of interest using techniques from shape calculus. We show...
journal article 2010
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Van der Zee, K.G. (author), Van Brummelen, E.H. (author), De Borst, R. (author)
In free-boundary problems, the accuracy of a goal quantity of interest depends on both the accuracy of the approximate solution and the accuracy of the domain approximation. We develop duality-based a posteriori error estimates for functional outputs of solutions of free-boundary problems that include both sources of error. The derivation of an...
journal article 2010
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Bin Zubair, H. (author)
Multigrid efficiency often suffers from inadequate coarse grid correction in different prototypic situations. We select a few problems, where coarse grid correction issues arise because of anisotropic coefficients, non-equidistant or non-uniform grid stretching, or inherent indefiniteness in the partial differential equation. Most of the work in...
doctoral thesis 2009
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Van der Zee, K.G. (author)
The simulation of complex physical phenomena, such as fluid–structure interaction, appears to be within reach in view of the significant progress in computing power over the last decades. Yet, we are still far away from what is desirable in an evermore-demanding, science-and-technology-based society. If, however, we are modest with what we need...
doctoral thesis 2009
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