Exponential Characteristic Spatial Quadrature for Discrete Ordinates Neutral Particle Transport in Two-Dimensional Cartesian Coordinates
Date of Award
9-1993
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Department of Engineering Physics
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.
AFIT Designator
AFIT-DS-ENP-93-07
DTIC Accession Number
ADA270458
Recommended Citation
Minor, Bryan M., "Exponential Characteristic Spatial Quadrature for Discrete Ordinates Neutral Particle Transport in Two-Dimensional Cartesian Coordinates" (1993). Theses and Dissertations. 6886.
https://scholar.afit.edu/etd/6886