Session: FSI-02-02 Flow-induced Vibration II

Paper Number: 63798

Start Time: Wednesday, July 14, 2021, 09:00 AM

63798 - Numerical Prediction of the Phase Difference in Tube Bundles Experiencing Streamwise Fluidelastic Instability 

Recent experimental investigations have shown that tube arrays can become unstable in the streamwise direction. This is contrary to the long-held notion that fluidelastic instability is only a concern in the direction transverse to the flow. The possiblity of streamwise fluidelastic instability (FEI) as a potential threat to the integrity of tube bundles was confirmed by the recent failures of newly installed replacement steam generators. A number of invvestigations were conducted to uncover the nature of this mechanism. A theoretical framework was developed by Hassan and Weaver (2016) to model streamwise fluidelastic instability in a bundle of flexible tubes. The model utilized a simple time lag expression for the flow channel area perturbation. The current work aims to develop a numerical model to precisely predict the flow perturbation characteristics in a tube bundle due to streamwise tube motion. Flow simulations were conducted for single phase fluid flow in a parallel triangle tub ebundle array with pitch-to-diameter ratios of 1.2, 1.5, and 1.7. The numerical model was benchmarked against numerical and experimental results available in the FEI literature. Simulations were carried out for a range of reduced flow velocities. The model results showed that the upstream flow perturbation magnitude and phase are different from those obtained downstream of the moving tube. The obtained flow perturbation characteristics were implemented in the Hassan and Weaver (2016) model and the streamwise FEI threshold was predicted.

Presenting Author: Marwan Hassan University of Guelph

Authors:

Sameer A Rehman University of Guelph
Salim El Bouzidi Canadian Nuclear Laboratories
Osama Elbanhawy University of Guelph
Marwan Hassan University of Guelph
David S Weaver McMaster University