An efficient three dimensional unstructured Euler solver is parallelized on a Cray Y-MP C90 shared memory computer and on an Intel Touchstone Delta distributed memory computer. This paper relates the experiences gaine...
详细信息
The complete exchange ('all-to-all personalized') communication pattern is at the heart of numerous important multicomputer algorithms. Recent research has shown how this pattern can efficiently be performed o...
详细信息
The complete exchange ('all-to-all personalized') communication pattern is at the heart of numerous important multicomputer algorithms. Recent research has shown how this pattern can efficiently be performed on circuit-switched hypercubes. However, on circuit-switched meshes, this pattern is difficult to perform efficiently because the sparsity of the mesh interconnect leads to severe link contention. The authors develop a family of algorithms that proceed by recursively carrying out a series of contention-free exchanges on subdivisions of the mesh. Each member of this family is useful for some range of the parameters: mesh size, message size, startup time, and data transmission and permutation rates. The authors describe the performance of their algorithms on the Touchstone Delta mesh.< >
A fully Sinc‐Galerkin method in both space and time is presented for fourth‐order time‐dependent partial differential equations with fixed and cantilever boundary conditions. The sine discretizations for the second...
作者：
Li, K.Tassoudji, M.A.Shin, R.T.Kong, J.A.Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics
Massachusetts Institute of Technology Cambridge Massachusetts 02139 Kevin Li:received his BS and SM degrees (1990) in Electrical Engineering and EE (Electrical Engineer's) degree (1991) from the Massachusetts Institute of Technology
where he is currently pursuing his PhD in Electrical Engineering. Since 1990 he has been the recipient of a United States Air Force Laboratory Graduate Fellowship. His main research interests include electromagnetic scattering radar cross section prediction and numerical techniques. Mr. Li is a member of Tau Beta Pi and a student member of IEEE. M. Ali Tassoudji:received his BS (1987) and MS (1989) degrees in Electrical Engineering from the University of Michigan
Ann Arbor. Since 1989 he has been a research assistant at the Massachusetts Institute of Technology where he is currently working towards his PhD in Electrical Engineering. His research interests include electromagnetic scattering and propagation modeling of microwave circuits and numerical techniques. Mr. Tassoudji is a member of IEEE and Eta Kappa Nu. Robert T. Shin:received his SB (1977)
SM (1980) and PhD (1984) in Electrical Engineering from the Massachusetts Institute of Technology. Since 1984 he has been a member of the Air Defense Techniques Group at MIT Lincoln Laboratory as a Research Staff member and as a Senior Staff member from 1989. His research interests are in the areas of electromagnetic wave scattering and propagation theoretical model development and data interpretation for microwave remote sensing. He is the coauthor ofTheory of Microwave Remote Sensing(Wiley 1985). Dr. Shin is a member of The Electromagnetics Academy IEEE American Geophysical Union Tau Beta Pi Eta Kappa Nu and Commission F of the International Union of Radio Science. Since 1987 he has served on the Editorial Board of theJournal of Electromagnetic Waves and Applications(JEWA). Jin Au Kong:is Professor of Electrical Enginee
The finite difference-time domain (FD-TD) technique is applied to the solution of Maxwell's equations. A computer program, which can be used to simulate and study numerous electromagnetic phenomena, is developed a...
The finite difference-time domain (FD-TD) technique is applied to the solution of Maxwell's equations. A computer program, which can be used to simulate and study numerous electromagnetic phenomena, is developed and implemented on an IBM 386 compatible personal computer. The FD-TD technique is a useful tool for students in electromagnetics. The technique is flexible and can be applied to many basic EM scattering and radiation problems. Because field solutions are found as a function of time, visualization of the propagation of the EM fields is possible. The FD-TD technique is implemented for a two-dimensional rectangular grid in conjunction with a second-order absorbing boundary condition. Both E- and H-field polarizations are analyzed. Finite objects consisting of dielectric, magnetic and conducting materials, and perfectly conducting infinite ground planes are modeled. Plane wave and line current sources are implemented. In addition to the capability of animating the propagation of the EM fields, radiation and scattering patterns can be generated.
The nonlinear time evolution of a second-mode instability in a Mach 4.5 wall-bounded flow is computed by solving the full compressible, time-dependent Navier-Stokes equations. High accuracy is achieved by using a Four...
详细信息
The nonlinear time evolution of a second-mode instability in a Mach 4.5 wall-bounded flow is computed by solving the full compressible, time-dependent Navier-Stokes equations. High accuracy is achieved by using a Fourier-Chebyshev collocation algorithm. Primarily inviscid in nature, second modes are characterized by high frequency and high growth rates compared to first modes. Time evolution of growth rate as a function of distance from the plate suggests this problem is amenable to the Stuart-Watson perturbation theory as generalized by Herbert.
Taylor-Couette flow, the shear-driven flow between concentric cylinders, exhibits a wide variety of instabilities and modal changes, especially for the case of finite length to gap ratio. The numerical simulations pre...
详细信息
Taylor-Couette flow, the shear-driven flow between concentric cylinders, exhibits a wide variety of instabilities and modal changes, especially for the case of finite length to gap ratio. The numerical simulations presented here capture many of the experimentally observed features, including the moderately high Reynolds number regime in which temporally aperiodic behavior is seen. The exponential decay of the temporal frequency spectrum of these modes in the simulations indicate such flows possess a low-order chaotic character. In this paper, the spectral collocation methods used in this study are described, select axisymmetric simulations are reviewed, and initial results from three-dimensional unsteady simulations are presented.
The purpose of this study is to investigate compressibility effects on the turbulence in homogeneous shear flow. We find that the growth of the turbulent kinetic energy decreases with increasing Mach number-a phenomen...
The three-dimensional Euler equations are solved on unstructured tetrahedral meshes using a multigrid strategy. The driving algorithm consists of an explicit vertex-based finite-element scheme, which employs an edge-b...
详细信息
Many times, routing of signal nets in the layout design of VLSI circuits turns out to be a bottleneck in designing complex chips, due to the inherent compute-intensive nature of this task. Parallel processing of the r...
详细信息
A method of efficiently computing turbulent compressible flow over complex two-dimensional configurations is presented. The method makes use of fully unstructured meshes throughout the entire flow field, thus enabling...
详细信息
A method of efficiently computing turbulent compressible flow over complex two-dimensional configurations is presented. The method makes use of fully unstructured meshes throughout the entire flow field, thus enabling the treatment of arbitrarily complex geometries and the use of adaptive meshing techniques throughout both viscous and inviscid regions of the flow field. Mesh generation is based on a locally mapped Delaunay technique in order to generate unstructured meshes with highly stretched elements in the viscous regions. The flow equations are discretized using a finite element Navier-Stokes solver, and rapid convergence to steady state is achieved using an unstructured multigrid algorithm, Turbulence modelling is performed using an inexpensive algebraic model, implemented for use on unstructured and adaptive meshes. Compressible turbulent flow solutions about multiple-element aerofoil geometries are computed and compared with experimental data.
暂无评论