Development of a Unit-Cell Based Multi-dimensional Heat Conduction Model for a Prismatic Fuel Block

Computational fluid dynamics (CFD) analysis has been successfully applied to obtain an accurate temperature distribution of prismatic fuel blocks in a very high temperature reactor (VHTR). However, it requires elaborate computational efforts to analyze whole prismatic fuel blocks due to complex geometry. In particular, tremendous efforts have to be devoted to generate computational grids for the CFD analysis. Such efforts might be huge burdens for a designer who wants a large number of calculations with various design options. In this work, a new multi-dimensional heat conduction model has been developed to overcome the demerits of the existing methods (e.g., CFD analysis and system analysis). This new model focuses on the regular arrangement of unit cells in a prismatic fuel block. The use of the unit cell concept enables an efficient generation of unstructured meshes without a mesh generator. This paper presents a brief outline of the new heat conduction model for a prismatic fuel block and some results of the verification and validation (V and V) study of the new model. The numerical results by the CFX 11 code are used for a comparison