Large eddy simulation of turbulent flow surrounding two simulated CANDU fuel bundles

Three-dimensional turbulent flow in one and a half simulated 43-element CANDU®1 fuel bundle at the inlet of a fuel channel is solved using large eddy simulation. Wake generated after the endplates and the flow development in the inlet bundle are investigated based on the simulation results. Spatial distribution and frequency spectra of fluid force components are also examined. The simulation results are compared to experimental data available in the literature as well as the measurements conducted by the authors. The current investigation provides a basic understanding of the fluid excitation in a simulated 43-element fuel bundle. The results may be used in a flow-induced vibration analysis for fuel bundles.

► Developed a comprehensive computational fluid dynamics model for coolant flow through CANDU fuel bundles.
► Discovered the cause of large unsteady flow excitations in CANDU fuel bundles.
► The fluid force obtained from the simulation model can be used to quantify CANDU fuel vibration and pressure tube fretting wear.