Accession Number : ADA020058

Title :   Effective Methods for Solution of Nonlinear Reactor Dynamics Problems Using Finite Elements.

Descriptive Note : Master's thesis,


Personal Author(s) : Olsen,Richard Allen

Report Date : DEC 1975

Pagination or Media Count : 122

Abstract : The solution of the nonlinear two-dimensional reactor dynamics equation subjected to prompt feedback conditions using the finite element technique leads to a matrix formulation. The task of this thesis is the development of computational techniques which allow the problem to be solved for large systems. Specifically, these techniques are: (1) the treatment of the nonlinearity on the element level, (2) the compacting of the sparce matrices to include only non-zero terms, and (3) the construction of a new computer code based on the Crank-Nicolson formulation for the solution of differential equations. To support the theory presented, test problems were solved by the original method, the linearized technique, and the Crank-Nicolson treatment. The results were analyzed and compared graphically. All three of the innovations developed in this thesis appear to be useful tools for solving nonlinear time dependent differential equations.

Descriptors :   *Finite element analysis, *Nuclear reactors, *Reactor feasibility studies, Reactor operation, Computer programming, Nonlinear differential equations, Vector spaces, Matrices(Mathematics), Feedback, Neutron cross sections, Neutron absorption, Problem solving, Computer applications, FORTRAN, Matrix displays

Subject Categories : Theoretical Mathematics
      Nuclear Power Plants and Fission Reactor Eng
      Nuclear Fission Reactors(non-power)

Distribution Statement : APPROVED FOR PUBLIC RELEASE