Accession Number : ADA270458

Title :   Exponential Characteristic Spatial Quadrature for Discrete Ordinates Neutral Particle Transport in Two-Dimensional Cartesian Coordinates.

Descriptive Note : Doctoral thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Minor, Bryan M.

Report Date : SEP 1993

Pagination or Media Count : 183

Abstract : The exponential characteristic spatial quadrature for discrete ordinates neutral particle transport with rectangular cells is developed. Numerical problems arising in the derivation required the development of exponential moment functions. These functions are used to remove indeterminant forms which can cause catastrophic cancellations. The EC method is positive and nonlinear. It conserves particles and satisfies first moment balance. Comparisons of the EC method's performance to other methods in optically thin and thick spatial cells were performed. For optically thin cells, the EC method was shown to converge to the correct answer, with third order truncation error in the thin cell limit. In deep penetration problems, the EC method attained its highest computational efficiencies compared to the other methods. For all the deep penetration problems examined, the number of spatial cells required by the EC method to attain a desired accuracy was less than the other methods.... Mathematics functions, Nuclear radiation, Nuclear engineering, Radiation attenuation, Radiation shielding, Transport theory, Radiation transport

Descriptors :   *CARTESIAN COORDINATES, *NUMERICAL QUADRATURE, *EXPONENTIAL FUNCTIONS, *NEUTRON TRANSPORT THEORY, ACCURACY, ATTENUATION, CELLS, COMPARISON, EFFICIENCY, ERRORS, INTEGRAL EQUATIONS, MATHEMATICS, MOMENTS, NEUTRAL, NUCLEAR ENGINEERING, NUCLEAR RADIATION, PARTICLES, PENETRATION, RADIATION, RADIATION ATTENUATION, RADIATION SHIELDING, TRUNCATION, TWO DIMENSIONAL.

Subject Categories : Fission Reactor Physics
      Statistics and Probability
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE