摘要:

The standard derivation of the linear discontinuous (LD) spatial discretization method for planar geometry transport problems is modified to produce an entire family of methods. This family is characterized by a real parameter which assumes the value = 3 in the usual LD method. This discretization scheme is investigated for positivity and accuracy as a function of . Numerical results are compared with exact analytic solutions for the simple rod model of transport theory.

ISSN:0041-1450    

DOI:10.1080/00411458908204689

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

We consider three different asymptotic limits of a model describing linear particle transport in a stochastic medium consisting of two randomly mixed immiscible fluids. These three limits are: (1) the fluid packets are small compared to the particle mean free path in the packet; (2) a small amount of large cross section fluid is admixed with a large amount of small cross section fluid; and (3) the angular dependence of the intensity (angular flux) is nearly isotropic. The first two limits reduce the underlying model, which consists of two coupled transport equations, to a single transport equation of the usual form. The third limit yields a two-equation diffusion approximation, and a boundary layer analysis gives boundary conditions for these two coupled diffusion equations.

ISSN:0041-1450    

DOI:10.1080/00411458908204690

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The response matrix method as used in reactor physics deals mostly with face averaged quantities. When homogenizing a region we use position independent boundary conditions. In both problems we neglect those solutions of the equation to be solved that belong to the zero average value along the boundary. In the case of the diffusion equation those solutions — called overtones — are studied on two examples. First the entering current distribution of an efficient analytical coarse- mesh model is assessed, then the widely applied quadratic entering current distribution.

ISSN:0041-1450    

DOI:10.1080/00411458908204691

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Absorbing boundary conditions for the transport equation governing the time evolution of the Wigner distribution function are derived. Local approximations are given which can be used to simulate quantum transport phenomena numerically on a finite domain and a numerical test example is presented.

ISSN:0041-1450    

DOI:10.1080/00411458908204692

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this paper, we study a relatively novel numerical technique, the discrete-cone (DCN) method, in transport theory. Specifically, we use previous results for the discrete-ordinate (SN) method to establish, under mathematically mild and physically reasonable conditions, the convergence of the discrete-cone method in the numerical solution of the monoenergetic transport equation for slab geometry.

ISSN:0041-1450    

DOI:10.1080/00411458908204693

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this paper we deal with a class of inverse problems for an operator-valued mapping in a Banach space, which is usually associated with a compact operator equation. Our aim is to remove the restriction of compactness. The existence, uniqueness and stability of the solution of the inverse problem are shown. The results obtained here are applied to an inverse problem for the transport equation in an inhomogeneous medium. An example is given to illustrate the relationship between stability and topology.

ISSN:0041-1450    

DOI:10.1080/00411458908204694

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0041-1450    

DOI:10.1080/00411458908204695

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor