Finite Element Analysis for Turbulent Flows of Incompressible Fluids in Fuel Rod Bundles

This paper deals with the application of the finite element method to solve the momentum equation for the central subchannel of a fuel rod bundle. The Galerkin procedure in the method of weighted residuals is used to form the nonlinear algebraic equations that are solved by means of the Newton-Raphson approach. For turbulent flow, the eddy diffusivities are determined by Prandtl's mixing length hypothesis. The mixing lengths perpendicular and parallel to the wall are calculated from geometrical conditions using relations obtained by various authors. The results obtained are critically compared with experimental data and also with those obtained by finite difference procedures. There is a close agreement between the finite element results and other calculated data. Corresponding results also show a good agreement with experimental data available.