Diffusion synthetic acceleration of the diamond differenced and linear discontinuous discrete ordinates equations in X-Y geometry

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5908958

AboAlfaraj, T G

The diffusion synthetic acceleration (DSA) method is a powerful, stable, efficient iteration method for solving neutron transport problems. However, the particular form of the DSA method encoded in the TWODANT computer code (for solving neutron transport problems in X-Y geometry) has been seen to exhibit poor performance as the spatial mesh size increases. In this thesis, Fourier-analyses this form of the DSA method, and theoretically explains these observations. An alternative approach, which produces a more consistent DSA method, is presented, and is shown to be much more stable and efficient than the form encoded in TWODANT. The linear discontinuous discrete ordinate method is a more accurate spatial discretization method than the diamond difference method used in TWODANT. However, the complex form of the DSA equations for this method makes it difficult to collapse them into an easily solvable form. In this thesis, he introduces an approximation that produces acceleration equations which can be put into the diamond difference form, and hence can be collapsed into an easily solvable form. A Fourier analysis and numerical experiments confirm that the method is stable and highly efficient for typical nuclear reactor problems.

• Research Organization: Michigan Univ., Ann Arbor, MI (USA)
• OSTI ID: 5908958
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COMPUTER CODES
DISCRETE ORDINATE METHOD
FOURIER ANALYSIS
ITERATIVE METHODS
MESH GENERATION
NEUTRON TRANSPORT THEORY
PERFORMANCE
PHYSICS
REACTOR PHYSICS
T CODES
TRANSPORT THEORY