Simulation of Laminar Pulsations in a Rectangular Duct Containing a Rod

Abstract

Flow pulsations in subchannel geometries are important in the homogenization of fluid temperatures within a fuel rod bundle cross-section. Recent experimental work by Gosset and Tavoularis has indicated that flow pulsations can occur under laminar conditions. This paper presents the results of computational fluid dynamics investigation of laminar flow pulsations in a single rod geometry matching the experimental geometry and conditions of Gosset and Tavoularis. A gap height to rod diameter ratio of 0.3 and Reynolds numbers of 718 and 900 were considered. Rough agreement between the simulations and the experimental results was obtained for the measured frequency, and the simulations revealed highly complex flow patterns throughout the duct cross-section.