Session: FSI-02-01 The David S. Weaver Memorial Session on Flow Induced Vibration: Tube Arrays

Paper Number: 125307

125307 - Geometrical Effect of Normal Square Array on Prediction of Fluidelastic Instability– Single Phase Air Flow 

Flow-induced vibrations (FIV) play a pivotal role in the design and operation of nuclear steam generators as they significantly can compromise their structural integrity and long-term performance. Among the various mechanisms contributing to FIV, fluidelastic instability (FEI) stands out as the most crucial phenomenon, capable of causing failures in short periods of time.  A recent incident involving the replacement of steam generators has brought attention to the elusive nature of this problem, emphasizing the urgency of understanding, and addressing FEI. This understanding is crucial for enhancing the design methodologies and operational guidelines, ultimately contributing to the advancement of nuclear energy technology.

A comprehensive series of experiments in an open loop wind tunnel was conducted, with a focus on the normal square array subjected to cross-flow. This study presents a systematic exploration of the array's geometric impact, encompassing factors like array pitch ratio, flexibility level, and flexibility direction on the onset of the fluidelastic instability. Remarkably, this investigation represents the first documented experimental observation of streamwise fluidelastic instability in the normal square array. The results underscore the vital role played by the array's pitch ratio and the number of flexible tubes on the array stability behavior, particularly in the transverse directions.

Keywords: Flow-induced Vibration, Fluidelastic Instability, Streamwise, In-plane FEI, Nuclear Steam Generators, Tube Bundle. 

Presenting Author: Amro Elhelaly University of Guelph

Presenting Author Biography: Amro Elhelaly is a Ph.D. candidate at the University of Guelph, supervision of Professor Marwan Hassan. His research focuses on the fascinating realm of fluid-structure interaction, with a specific interest on flow-induced vibration in steam generator tube arrays.

Authors:

Amro Elhelaly University of Guelph
Marwan Hassan University of Guelph