Numerical Simulation of Flow Through Nuclear Fuel Bundles With Angular Misalignments

Abstract

Comprehensive computational fluid dynamics (CFD) models are developed and analyzed in this paper to study the three-dimensional flow through simulated nuclear fuel bundles with angular misalignments inside a pressure tube. The large eddy simulation (LES) scheme is employed to solve the large scale complex computational models with an aim to understanding the effects of the bundle-to-bundle angular misalignments on unsteady flow and flow-induced excitations on the fuel bundle structures. The proposed numerical scheme is validated with both numerical and experimental work available in the literature. Numerical results obtained from the current computational models indicate the presence of significant lateral or cross-flow in the bundle-to-bundle interface region for bundles with angular misalignments. The mean and the rms values of the lateral fluid excitations on the first bundle are found to be sensitive with respect to the change in angular misalignments between bundles.