Download or read book Advances in Time Domain Electromagnetic Simulation Capabilities Through the Use of Overset Grids and Massively Parallel Computing written by Douglas C. Blake and published by . This book was released on 1997-03-01 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new methodology is presented for conducting numerical simulations of electromagnetic scattering and wave propagation phenomena. Technologies from several scientific disciplines, including computational fluid dynamics, computational electromagnetics, and parallel computing, are uniquely combined to form a simulation capability that is both versatile and practical. In the process of creating this capability, work is accomplished to conduct the first study designed to quantify the effects of domain decomposition on the performance of a class of explicit hyperbolic partial differential equations solvers; to develop a new method of partitioning computational domains comprised of overset grids; and to provide the first detailed assessment of the applicability of overset grids to the field of computational electromagnetics. Furthermore, the first Finite Volume Time Domain (FVTD) algorithm capable of utilizing overset grids on massively parallel computing platforms is developed and implemented. Results are presented for a number of scattering and wave propagation simulations conducted using this algorithm, including two spheres in close proximity and a finned missile.
Download or read book 40th AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2002 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1997 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 31st AIAA Plasmadynamics and Lasers Conference written by and published by . This book was released on 2000 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2001 with total page 1304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 28th Plasmadynamics and Lasers Conference written by and published by . This book was released on 1997 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 38th Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 2000 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 36th Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 1998 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1996 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Domain Connectivity Among Systems of Overset Grids written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-17 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This progress report describes research performed to achieve algorithmic improvements in the use of overset grids for the computation of unsteady flowfields about geometrically complex and moving component configurations. A hole-map computational method is detailed that reduces computational demand and corresponding demand on human resources. Results indicate that the method is both efficient and flexible for use in complex simulation cases. Tests were performed on shuttle orbiter/external tank, wing/store, and V-22 tilt-rotor configurations. The number of simulated points and the corresponding time on a SGI 4D-210 workstation are presented. Meakin, Robert L. Unspecified Center NASA-CR-193390, NAS 1.26:193390 NCC2-783...
Download or read book Simulation and Visualization on the Grid written by Björn Engquist and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is now 30 years since the network for digital communication, the ARPA-net, first came into operation. Since the first experiments with sending electronic mail and performing file transfers, the development of networks has been truly remarkable. Today's Internet continues to develop at an exponential rate that even surpasses that of computing and storage technologies. About five years after being commercialized, it has become as pervasive as the tele phone had become 30 years after its initial deployment. In the United States, the size of the Internet industry already exceeds that of the auto industry, which has been in existence for about 100 years. The exponentially increas ing capabilities of communication, computing, and storage systems is also reshaping the way science and engineering are pursued. Large-scale simulation studies in chemistry, physics, engineering, and sev eral other disciplines may now produce data sets of ,several terabytes or petabytes. Similarly, almost all measurements today produce data in digital form, whether from collections of sensors, three-dimensional digital images, or video. These data sets often represent complex phenomena that require rich visualization capabilities and efficient data-mining techniques to under stand. Furthermore, the data may be produced and archived in several differ ent locations, and the analysis carried out by teams with members at several locations-possibly distinct from those with significant storage, computation, or visualization facilities. The emerging computational Grids enable the transparent use of remote instruments, computational and data resources.
Download or read book Massively Parallel Finite difference Time domain Simulators written by Magathi Jayaram and published by . This book was released on 2006 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiblock Grid Generation written by Nigel P. Weatherill and published by Vieweg+Teubner Verlag. This book was released on 2012-07-01 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Fluid Dynamics research, especially for aeronautics, continues to be a rewarding and industrially relevant field of applied science in which to work. An enthusiastic international community of expert CFD workers continue to push forward the frontiers of knowledge in increasing number. Applications of CFD technology in many other sectors of industry are being successfully tackled. The aerospace industry has made significant investments and enjoys considerable benefits from the application of CFD to its products for the last two decades. This era began with the pioneering work ofMurman and others that took us into the transonic (potential flow) regime for the first time in the early 1970's. We have also seen momentous developments of the digital computer in this period into vector and parallel supercomputing. Very significant advances in all aspects of the methodology have been made to the point where we are on the threshold of calculating solutions for the Reynolds-averaged Navier-Stokes equations for complete aircraft configurations. However, significant problems and challenges remain in the areas of physical modelling, numerics and computing technology. The long term industrial requirements are captured in the U. S. Governments 'Grand Challenge' for 'Aerospace Vehicle Design' for the 1990's: 'Massively parallel computing systems and advanced parallel software technology and algorithms will enable the development and validation of multidisciplinary, coupled methods. These methods will allow the numerical simulation and design optimisation of complete aerospace vehicle systems throughout the flight envelope'.
Download or read book Mapping Unstructured Grid Computations to Massively Parallel Computers written by Steven Warren Hammond and published by . This book was released on 1992 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "This thesis investigates the mapping problem: assign the tasks of a parallel program to the processors of a parallel computer such that the execution time is minimized. First, a taxonomy of objective functions and heuristics used to solve the mapping problem is presented. Next, we develop a highly parallel heuristic mapping algorithm, called Cyclic Pairwise Exchange (CPE), and discuss its place in the taxonomy. CPE uses local pairwise exchanges of processor assignments to iteratively improve an initial mapping. A variety of initial mapping schemes are tested and recursive spectral bipartitioning (RSB) followed by CPE is shown to result in the best mappings. For the test cases studied here, problems arising in computational fluid dynamics and structural mechanics on unstructured triangular and tetrahedral meshes, RSB and CPE outperform methods based on simulated annealing. Much less time is required to do the mapping and the results obtained are better. Compared with random and naive mappings, RSB and CPE reduce the communication time twofold for the test problems used. Finally, we use CPE in two applications on a CM-2. The first application is a data parallel mesh-vertex upwind finite volume scheme for solving the Euler equations on 2-D triangular unstructured meshes. CPE is used to map grid points to processors. The performance of this code is compared with a similar code on a Cray-YMP and an Intel iPSC/860. The second application is parallel sparse matrix-vector multiplication used in the iterative solution of large sparse linear systems of equations. We map rows of the matrix to processors and use an inner-product based matrix-vector multiplication. We demonstrate that this method is an order of magnitude faster than methods based on scan operations for our test cases."
Download or read book Time domain Solvers for Complex media Electrodynamics and Plasma Physics written by Burkay Donderici and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this dissertation, several extensions for two popular electromagnetic simulation methods: finite-different time-domain (FDTD) and finite-element time-domain (FETD), are presented. These extensions aim to increase the geometrical flexibility and modeling capabilities in simulation of Maxwell's equations. Since straight-forward extensions to these methods produce numerical artifacts that pollute the results and reduce accuracy, alternative strategies have been sought. Various methodologies are explored here to address these issues: A E-B mixed-vector FETD implementation based on first order Maxwell equations is introduced. In this method a mix of electric and magnetic field variables are used, where an edge element expansion is used for the electric field and face element expansion is used for the magnetic field. Compared to the standard FETD methods, it can produce several advantages without any significant computational drawback: (i) it eliminates the spurious linear growth in time that may exist in the standard schemes; (ii) it produces energy-conserving schemes under appropriate time-discretization; (iii) it can be easily extended to frequency-dispersive media; (iv) it provides a natural path for hybridization with FDTD. Exploiting item (iii), E-B mixed-vector FETD is extended to inhomogeneous doubly-dispersive media. A conformal-PML implementation is also proposed for efficient simulation of open-domain boundaries by significantly reducing the buffer regions in the computational domain. Despite the advantages, finite-element simulations require solution of a linear system of equations which, in most practical problems, highly computationally intense. A hybrid FDTD-FETD method is introduced to alleviate this issue. The hybridization can result in significant optimization in computational cost by assigning detailed portion of the computational domain to FETD, while assigning the remaining to FDTD. Finally, a subgridding by domain-overriding (SGDO) methodology for full electromagnetic particle-in-cell (PIC) simulations is presented. Combined with relaxation methods, SGDO can produce significant improvements in PIC simulation accuracy.
Download or read book Optimal Spatial Grids for Efficient Numerical Simulation of Time domain Electromagnetic Phenomena by Finite Methods written by Aravind Ramachandran and published by ProQuest. This book was released on 2009 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: In particular, a novel application of optimal grids to perfectly matched layer absorbing boundary conditions is presented. In this development, a single optimal grid combining the interior computational and exterior absorbing regions (with Dirichlet or Neumann boundary) is constructed, and the perfectly matched layer loss parameters are defined along this grid.
