A nodal diffusion technique for synthetic acceleration of nodal S /sup n/ calculations

Journal Article · Mon Jul 01 04:00:00 EDT 1985 · Nucl. Sci. Eng.; (United States)

OSTI ID:6073359

Khalil, H

A diffusion theory method is developed for synthetic acceleration of nodal S /sub n/ calculations in multidimensional Cartesian geometries. The diffusion model is derived from the spatially continuous diffusion equation by applying spatial approximations that are P expansions of the corresponding approximations made in solving the transport equation. The equations of the diffusion model are formulated in a way that permits application of existing and highly efficient nodal diffusion theory techniques to their numerical solution. Test calculations for several benchmark problems in X-Y geometry are presented to illustrate the efficiency and stability of the acceleration metho when applied to a ''constant-linear'' nodal transport approximation. The method is shown to yield pointwise flux convergence of 10 U in fewer than ten synthetic iterations for all problems considered and to require substantially less computational effort than unaccelerated solutions.

• Research Organization: Argonne National Laboratory, Argonne, IL
• OSTI ID: 6073359
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 90; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CARTESIAN COORDINATES
CONVERGENCE
COORDINATES
DIFFERENTIAL EQUATIONS
EQUATIONS
ITERATIVE METHODS
NEUTRON DIFFUSION EQUATION
NEUTRON TRANSPORT THEORY
NUMERICAL SOLUTION
SERIES EXPANSION
TRANSPORT THEORY