3 edition of Absorbing boundary conditions for exterior problems found in the catalog.
Absorbing boundary conditions for exterior problems
by Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, National Technical Information Service, distributor in Hampton, VA, [Springfield, Va
Written in English
|Statement||by S.I. Hariharan|
|Series||ICASE report -- no. 85-33, NASA contractor report -- 177944, NASA contractor report -- NASA CR-177944|
|Contributions||Institute for Computer Applications in Science and Engineering|
|The Physical Object|
Absorbing boundary conditions for exterior problems - NASA/ADS Elliptic and hyperbolic problems in unbounded regions are considered. These problems, when one wants to solve them numerically, have the difficulty of prescribing boundary conditions at infinity. Computationally, one needs a finite region in which to solve these problems. An exact nonreflecting boundary condition is derived for the time-dependent elastic wave equation in three space dimensions. This condition holds on a spherical surface $\mathcal B$, outside of which the medium is assumed to be linear, homogeneous, isotropic, and source-free. It is local in time, nonlocal on $\mathcal B$, and involves only first derivatives of the solution.
Abstract. We consider the problem of constructing absorbing boundary conditions for the multi-dimensional wave equation. Here we work directly with a difference approximation to the equation, rather than first finding analytical boundary conditions and then discretizing the analytical conditions. Get this from a library! Nonlinear acoustic wave propagation in atmosphere ; Absorbing boundary conditions for exterior problems: semi annual status report, period November 1, to Ap [S I Hariharan; United States. National Aeronautics and Space Administration.].
Among numerical methods applied in acoustics, the Finite Element Method (FEM) is normally favored for interior problems whereas the Boundary Element Method (BEM) is quite popular for exterior ones. That is why this valuable reference provides a complete survey of methods for computational acoustics, namely FEM and BEM. Book Search tips Selecting this option will search all publications across the (). “ The application of integral equation methods to the numerical solution of some exterior boundary-value problems,” Proc the true eigenfrequencies of cavities with absorbing boundary conditions are also complex numbers for which imaginary parts.
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ABSORBING BOUNDARY CONDITIONS FOR EXTERIOR PROBLEMS by S. IIaritiaran" 1. It?t__ro,uc t ion Mariy rorriiulations arising from physical tiaturc yield problems in tin- bouriclecl regions. Mat hernatical forrtiulatiotis of such problems yield govern- ing partial (liffereritial equations in or near a given tlortiain in such a fashion.
Get this from a library. Absorbing boundary conditions for exterior problems. [S I Hariharan; Institute for Computer Applications in Science and Engineering.]. A method developed recently by the authors for generating simple, yet efficient, time-domain absorbing boundaries is applied to Absorbing boundary conditions for exterior problems book with nonlinearities.
The procedure, involving finite elements for the interior region in addition to the absorbing boundary representing the exterior region, is illustrated for the case of an elastic, semi-infinite bar embedded in an elastoplastic Author: J.
Bielak, R. MacCamy, A. Trochanis. In order to render the problem well-posed, it is essential to devise an appropriate mechanical model, numerical technique or absorbing boundary condition (ABC) at the truncating boundary so that the effects of the exterior region (on the interior region) can be taken into account by: 3.
This paper addresses the construction of dierent families of absorbing boundary conditions for the one- and two-dimensional Schrodinger equation with a general variable nonlinear potential. Various semi-discrete time schemes are built for. Absorbing boundary conditions and perfectly matched layers in wave propagation problems Frédéric Nataf To cite this version: Frédéric Nataf.
Absorbing boundary conditions and perfectly matched layers in wave propagation problems. Direct and Inverse problems in Wave Propagation and Applications, 14, de Gruyter, pp,Radon Ser.
equation for strong-ﬁeld problems on a grid using exterior complex scaling ECS as an absorbing boundary condition. It is shown that the ECS method can be applied in both the length and the velocity gauge as long as appropriate approximations are applied in the ECS transformation of the electron-ﬁeld coupling.
It is found that. Without absorbing boundary conditions one has to solve a problem with the matrix K while with absorbing boundary conditions the problem is solved with the matrix K − M v A ˜. In Table 5, we compare the number of non zero elements in the matrix M v A ˜ for different values of N i and for the frequency Hz.
Abstract —This paper reviews the absorbing boundary conditions (ABCs) used in the past years to solve open problems with such numerical techniques as the finite difference or the finite element methods. Numerous ABCs have been proposed over the years in the various domains of Physics.
The review is limited to the local ABCs. Numerical experiments with problems in jet acoustics verify the practical nature and utility of the boundary conditions.
exterior aerodynamics, absorbing boundary conditions. Absorbing boundary conditions for the one-dimensional Schr odinger equation with an exterior repulsive potential Xavier Antoine, Christophe Bessey, Pauline Klein Abstract. Mathematical constructions and comparisons of accurate absorbing boundary boundary condition answering the problem is the so-called Transparent Boundary Condition (TBC.
Discrete Non-Local Absorbing Boundary Condition for exterior problems governed by Helmholtz equation. for solving radiators and scattering problems.
We also compare their performance to the second order absorbing boundary condition (BGT2) designed by Bayliss, Gunzburger and Turkel when expressed in prolate spheroidal coordinates. The analysis reveals that, in the low frequency regime, the new second order DtN condition (DtN2) retains a good level of accuracy regardless of the slenderness of the boundary.
A Friendly Review of Absorbing Boundary Conditions and Perfectly Matched Layers for Classical and Relativistic Quantum Waves Equations X. Antoinea, E. Lorinb,c and Q. Tanga aInstitut Elie Cartan de Lorraine, Universit e de Lorraine, UMRInria Nancy-Grand Est (SPHINX Team), F Vandoeuvre-l es-Nancy Cedex, France; bCentre de Recherches.
What is Absorbing Boundary Conditions (ABCs). Definition of Absorbing Boundary Conditions (ABCs): Are artificial absorbing layer for wave equations, commonly used to truncate computational regions in FDTD method to simulate problems with open boundaries.
Absorbing boundary conditions have been developed for various types of problems to truncate inﬁnite domains in order to perform computations. But absorbing boundary conditions have a second, recent and important application: parallel computing.
We show that absorbing boundary conditions are essential for a good performance of the Schwarz. The finite element method is employed to approximate the solutions of the Helmholtz equation for water wave radiation and scattering in an unbounded domain.
A discrete, non-local and non-reflecting boundary condition is specified at an artificial external boundary by the DNL method, yielding an equivalent problem that is solved in a bounded domain.
This procedure formulates a boundary. Topics include proof of the existence of wave operators, some special equations of mathematical physics — including Maxwell equations, the linear equations of elasticity and thermoelasticity, and the plate equation — exterior boundary value problems, radiation conditions, and limiting absorption : Rolf Leis.
CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Abstract. This paper addresses the construction of different families of absorbing boundary conditions for the one- and two-dimensional Schrödinger equation with a general variable nonlinear potential.
Various semi-discrete time schemes are built for the associated initial boundary value problems. TOWARDS PERFECTLY ABSORBING BOUNDARY CONDITIONS FOR EULER EQUATIONS M.
Ehtesham Hayder Fang Q. Hu M. Yousuff Hussaini NASA Contract No. NASI May Institute for Computer Applications in Science and Engineering NASA Langley Research Center Hampton, VA Operated by Universities Space Research Association National.
2. Design of High-Order Absorbing Boundary Conditions Denote the spatial coordinate by x, which for one-dimensional case is x = x, two-dimensional case is x = (#,2/), and three-dimensional case is x = (x,y,z). Denote the infinity domain by ft, the computational domain by the boundary by T = d ft, and the exterior domain by fte = ft 'fti.() Limitation of using absorbing boundary condition to solve the problem of scattering from a cavity in metallic screens.
IEEE Antennas and Propagation Society International Symposium, () Acoustic scattering from a solid aluminum cylinder in contact with a sand sediment: Measurements, modeling, and interpretation.Exterior acoustic problems occur in a wide range of applications, making the finite element analysis of such problems a common practice in the engineering community.
Various methods for truncating infinite exterior domains have been developed, including absorbing boundary conditions, infinite elements, and more recently, perfectly matched.