Author: Siti Sarah KamaludinPublisher:
ISBN:
Category : Adaptive computing systems
Languages : en
Pages : 208
Book Description
The Hp-adaptive Finite Element Method for Three Dimensional Multiphysics
Author: Siti Sarah KamaludinPublisher:
ISBN:
Category : Adaptive computing systems
Languages : en
Pages : 208
Book Description
A Scalable Hp-adaptive Finite Element Software with Applications in Fiber Optics
Author: Stefan Klaus Wilhelm HennekingPublisher:
ISBN:
Category :
Languages : en
Pages : 382
Book Description
In this dissertation, we present a scalable parallel version of hp3D—a finite element (FE) software for analysis and discretization of complex three-dimensional multiphysics applications. The developed software supports hybrid MPI/OpenMP parallelism for large-scale computation on modern manycore architectures. The focus of the effort lies on the development and optimization of the parallel software infrastructure underlying all distributed computation. We discuss the challenges of designing efficient data structures for isotropic and anisotropic hp-adaptive meshes with tetrahedral, hexahedral, prismatic, and pyramidal elements supporting discretization of the exact sequence energy spaces. While the code supports standard Galerkin methods, special emphasis is given to systems arising from discretization with the discontinuous Petrov–Galerkin (DPG) method. The method guarantees discrete stability by employing locally optimal test functions, and it has a built-in error indicator which we exploit to guide mesh adaptivity. In addition to interfacing with third-party packages for various tasks, we have developed our own tools including a parallel nested dissection solver suitable for scalable FE computation of waveguide geometries. We present weak-scaling results with up to 24576 CPU cores and numerical simulations with more than one billion degrees of freedom. The new software capabilities enable solution of challenging wave propagation problems with important applications in acoustics, elastodynamics, and electromagnetics. These applications are difficult to solve in the high-frequency regime because the FE discretization suffers from significant numerical pollution errors that increase with the wavenumber. It is critical to control these errors to obtain a stable and accurate method. We study the pollution effect for waveguide problems with more than 8000 wavelengths in the context of robust DPG FE discretizations for the time-harmonic Maxwell equations. We also discuss adaptive refinement strategies for multi-mode fiber waveguides where the propagating transverse modes must be resolved sufficiently. Our study shows the applicability of the DPG error indicator to this class of problems. Finally, we present both modeling and computational advancements to a unique three-dimensional DPG FE model for the simulation of laser amplification in a fiber amplifier. Fiber laser amplifiers are of interest in communication technology, medical applications, military defense capabilities, and various other fields. Silica fiber amplifiers can achieve high-power operation with great efficiency. At high optical intensities, multi-mode amplifiers suffer from undesired thermal coupling effects which pose a major obstacle in power-scaling of such devices. Our nonlinear 3D vectorial model is based on the time-harmonic Maxwell equations, and it incorporates both amplification via an active dopant and thermal effects via coupling with the heat equation. The model supports co-, counter-, and bi-directional pumping configurations, as well as inhomogeneous and anisotropic material properties. The high-fidelity simulation comes at the cost of a high-order FE discretization with many degrees of freedom per wavelength. To make the computation more feasible, we have developed a novel longitudinal model rescaling, using artificial material parameters with the goal of preserving certain quantities of interest. Numerical tests demonstrate the applicability and utility of this scaled model in the simulation of an ytterbium-doped, step-index fiber amplifier that experiences laser amplification and heating
Computing with hp-ADAPTIVE FINITE ELEMENTS
Author: Leszek DemkowiczPublisher: Chapman and Hall/CRC
ISBN: 9781584886723
Category : Science
Languages : en
Pages : 0
Book Description
With a focus on 1D and 2D problems, the first volume of Computing with hp-ADAPTIVE FINITE ELEMENTS prepared readers for the concepts and logic governing 3D code and implementation. Taking the next step in hp technology, Volume II Frontiers: Three-Dimensional Elliptic and Maxwell Problems with Applications presents the theoretical foundations of the 3D hp algorithm and provides numerical results using the 3Dhp code developed by the authors and their colleagues. The first part of the book focuses on fundamentals of the 3D theory of hp methods as well as issues that arise when the code is implemented. After a review of boundary-value problems, the book examines exact hp sequences, projection-based interpolation, and De Rham diagrams. It also presents the 3D version of the automatic hp-adaptivity package, a two-grid solver for highly anisotropic hp meshes and goal-oriented Krylov iterations, and a parallel implementation of the 3D code. The second part explores several recent projects in which the 3Dhp code was used and illustrates how these applications have greatly driven the development of 3D hp technology. It encompasses acoustic and electromagnetic (EM) scattering problems, an analysis of complex structures with thin-walled components, and challenging simulations of logging tools. The book concludes with a look at the future of hp methods. Spearheaded by a key developer of this technology with more than 20 years of research in the field, this self-contained, comprehensive resource will help readers overcome the difficulties in coding hp-adaptive elements.
The Finite Element Method for Three-Dimensional Thermomechanical Applications
Author: Guido DhondtPublisher: John Wiley & Sons
ISBN: 0470857625
Category : Science
Languages : en
Pages : 362
Book Description
Though many 'finite element' books exist, this book provides a unique focus on developing the method for three-dimensional, industrial problems. This is significant as many methods which work well for small applications fail for large scale problems, which generally: are not so well posed introduce stringent computer time conditions require robust solution techniques. Starting from sound continuum mechanics principles, derivation in this book focuses only on proven methods. Coverage of all different aspects of linear and nonlinear thermal mechanical problems in solids are described, thereby avoiding distracting the reader with extraneous solutions paths. Emphasis is put on consistent representation and includes the examination of topics which are not frequently found in other texts, such as cyclic symmetry, rigid body motion and nonlinear multiple point constraints. Advanced material formulations include anisotropic hyperelasticity, large strain multiplicative viscoplasticity and single crystal viscoplasticity. Finally, the methods described in the book are implemented in the finite element software CalculiX, which is freely available (www.calculix.de; the GNU General Public License applies). Suited to industry practitioners and academic researchers alike, The Finite Element Method for Three-Dimensional Thermomechanical Applications expertly bridges the gap between continuum mechanics and the finite element method.
Computing with hp-ADAPTIVE FINITE ELEMENTS
Author: Leszek DemkowiczPublisher: CRC Press
ISBN: 1420011693
Category : Mathematics
Languages : en
Pages : 437
Book Description
With a focus on 1D and 2D problems, the first volume of Computing with hp-ADAPTIVE FINITE ELEMENTS prepared readers for the concepts and logic governing 3D code and implementation. Taking the next step in hp technology, Volume II Frontiers: Three-Dimensional Elliptic and Maxwell Problems with Applications presents the theoretical foundations of the
H-P Adaptive Methods for Finite Element Analysis of Aerothermal Loads in High-speed Flows
Author: Advances in Intelligent Modelling and Simulation
Author: Aleksander ByrskiPublisher: Springer
ISBN: 364228888X
Category : Technology & Engineering
Languages : en
Pages : 377
Book Description
The human capacity to abstract complex systems and phenomena into simplified models has played a critical role in the rapid evolution of our modern industrial processes and scienti c research. As a science and an art, Modelling and Simulation have been one of the core enablers of this remarkable human trace, and have become a topic of great importance for researchers and practitioners. This book was created to compile some of the most recent concepts, advances, challenges and ideas associated with Intelligent Modelling and Simulation frameworks, tools and applications. The rst chapter discusses the important aspects of a human interaction and the correct interpretation of results during simulations. The second chapter gets to the heart of the analysis of entrepreneurship by means of agent-based modelling and simulations. The following three chapters bring together the central theme of simulation frameworks, rst describing an agent-based simulation framework, then a simulator for electrical machines, and nally an airborne network emulation environment. The two subsequent chapters discuss power distribution networks from different points of view|anticipation and optimization of multi-echelon inventory policy. After that, the book includes also a group of chapters discussing the mathematical modelling supported by veri cation simulations, and a set of chapters with models synthesised by means of arti cial intelligence tools and complex automata framework. Lastly, the book includes a chapter introducing the use of graph-grammar model for generation of threedimensional computational meshes and a chapter focused on the experimental and computational results regarding simulation of aero engine vortexes. Authors believe, that this book is a valuable reference to researchers and practitioners in the eld, as well as an inspiration to those interested in the area of Intelligent Modelling and Simulation.
Computing with hp-ADAPTIVE FINITE ELEMENTS
Author: Leszek DemkowiczPublisher: Chapman and Hall/CRC
ISBN: 9781584886723
Category : Science
Languages : en
Pages : 0
Book Description
With a focus on 1D and 2D problems, the first volume of Computing with hp-ADAPTIVE FINITE ELEMENTS prepared readers for the concepts and logic governing 3D code and implementation. Taking the next step in hp technology, Volume II Frontiers: Three-Dimensional Elliptic and Maxwell Problems with Applications presents the theoretical foundations of the 3D hp algorithm and provides numerical results using the 3Dhp code developed by the authors and their colleagues. The first part of the book focuses on fundamentals of the 3D theory of hp methods as well as issues that arise when the code is implemented. After a review of boundary-value problems, the book examines exact hp sequences, projection-based interpolation, and De Rham diagrams. It also presents the 3D version of the automatic hp-adaptivity package, a two-grid solver for highly anisotropic hp meshes and goal-oriented Krylov iterations, and a parallel implementation of the 3D code. The second part explores several recent projects in which the 3Dhp code was used and illustrates how these applications have greatly driven the development of 3D hp technology. It encompasses acoustic and electromagnetic (EM) scattering problems, an analysis of complex structures with thin-walled components, and challenging simulations of logging tools. The book concludes with a look at the future of hp methods. Spearheaded by a key developer of this technology with more than 20 years of research in the field, this self-contained, comprehensive resource will help readers overcome the difficulties in coding hp-adaptive elements.
Computing with HP-Adaptive Finite Element: One and Two Dimensional Elliptic and Maxwell Problems
Author: Leszek DemkowiczPublisher:
ISBN: 9781280733802
Category :
Languages : en
Pages : 398
Book Description
The second volume of "Computing with HP-Adaptive Finite Elements: Three Dimensional Elliptic and Maxwell Problems with Applications" organizes its comprehensive coverage into two parts. The first section focuses on the fundamentals of three-dimensional theory of HP methods and implementation issues. The second section presents several applications that reflect various projects for which the three-dimensional HP code has been used in recent years. The book concludes with future directions for the development of HP methods and specialized applications as acoustic scattering. All numerical results discussed in the text have been obtained using three-dimensional HP code.
Author: Siti Sarah Kamaludin