The finite difference approach poses the major problem to keep the exact values of material zone areas/volumes in any geometrical simulation for transport calculations. When this requirement is not thoroughly fulfilled, updating density values may be necessary in order to conserve material zone masses. This paper describes a method to conserve mass of geometrically complex material zones simulated on both Cartesian and cylindrical mesh grids and its implementation in BOT3P5.0, which is the latest version of the BOT3P code package, publicly and freely available from the Organization for Economic Cooperation and Development/Nuclear Energy Agency (OECD/NEA) Data Bank. BOT3P5.0 lets users optionally require as refined a computation as desired of the possible area/volume error of material zones due to the stair-cased geometry representation, and automatically corrects material densities in order to globally conserve masses. B0T3P5.0 optionally stores on binary outputs the detailed material zone distribution map inside each cell of the mesh grid, according to a sub-mesh grid refinement defined in input by the user and the area/volume fraction distribution of the different material zones contained in meshes at zone interfaces. That allows also a local (per cell) density correction in alternative to the approach of a uniform density correction on the whole zone domain and potentially makes it possible to perform material zone homogenisation locally and transport analyses with more accuracy.
|Titolo:||A General Method to Conserve Mass in Complex Geometry Simulation on Mesh Grids and Its Implementation in BOT3P5.0|
|Data di pubblicazione:||29-set-2006|
|Appare nelle tipologie:||5.2 Documento in Garanzia della Qualità|