The adjoint variational nodal method

Conference · Fri Jan 01 04:00:00 EST 1993 · Transactions of the American Nuclear Society; (United States)

OSTI ID:6904522

Laurin-Kovitz, K; Lewis, E E ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

The widespread use of nodal methods for reactor core calculations in both diffusion and transport approximations has created a demand for the corresponding adjoint solutions as a prerequisite for performing perturbation calculations. With some computational methods, however, the solution of the adjoint problem presents a difficulty; the physical adjoint obtained by discretizing the adjoint equation is not the same as the mathematical adjoint obtained by taking the transpose of the coefficient matrix, which results from the discretization of the forward equation. This difficulty arises, in particular, when interface current nodal methods based on quasi-one-dimensional solution of the diffusion or transport equation are employed. The mathematical adjoint is needed to perform perturbation calculations. The utilization of existing nodal computational algorithms, however, requires the physical adjoint. As a result, similarity transforms or related techniques must be utilized to relate physical and mathematical adjoints. Thus far, such techniques have been developed only for diffusion theory.

• OSTI ID: 6904522
• Report Number(s): CONF-931160--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 69
• Country of Publication: United States
• Language: English

Related Subjects

663610* -- Neutron Physics-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ADJOINT FLUX
ALGORITHMS
ANALYTICAL SOLUTION
DISPERSIONS
KINETICS
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
MIXTURES
NEUTRON FLUX
NEUTRON TRANSPORT THEORY
RADIATION FLUX
REACTOR KINETICS
SOLUTIONS
TRANSPORT THEORY