On the numerical solution of two-dimensional equation in diffusion approximation by the finite element method eliminating the peculiarities in calculational net nodes

The problems connected with numerical realization of an algorithm for solving the two-dimensional neutron diffusion equation by the finite element method are studied. An expression for the distribution function of one-group neutron flux in the vicinity of singular points is obtained. Analytical expressions for power indexes of singularity functions for multizone problems of practical interest are derived. The problems of numerical realization of the variational-difference scheme with singularity elimination are considered. The results of calculation studies on the convergence of some problems with singular points using the scheme without singularity elimination are given too