PREDICTION OF TWO-DIMENSIONAL NATURAL CONVECTION IN ENCLOSURES WITH INNER BODIES OF ARBITRARY SHAPES

Abstract

The numerical prediction of laminar natural convection in two-dimensional enclosures with inner bodies of irregular but basically cylindrical shape is the subject of this paper. This problem models, for example, the fluid dynamics in a nuclear spent-fuel storage container in which the inner body represents a tight water or a fast breeder reactor fuel assembly

The solution method described employs a nonorthogonal coordinate system in which the surfaces of the inner and outer boundaries coincide with coordinate surfaces. The coordinate system is generated with simple algebraic expressions. The transformed equations of motion and energy are derived on a control volume basis with central and upwind finite differences. Details of the derivation are provided. The discretiigd equations are solved within the framework of the Simplest scheme for orthogonal systems. Application of the solution methodology is illustrated with three examples.