Session: FSI-02-01 Tube Arrays - 1

Paper Number: 107434

107434 - Geometrical Effect of Tube Array on Prediction of Fluidelastic Instability– Single Phase Air Flow 

Flow-induced vibrations (FIV) is a major consideration in the design of the shell and tube heat exchangers. Among the FIV excitation mechanisms, fluidelastic instability (FEI) is by far the most important mechanism that can significantly compromise the structural integrity of tube arrays. Traditionally, FEI was thought to only occur in the transverse direction.  The recent tube failures of replacement steam generators showed that FEI could occurs in the streamwise direction and can be equally devastating.  This has sparked intensive efforts to uncover the nature of this new phenomenon. 

The current work presents an experimental investigation program which initiated to systematically uncover fundamental aspects of this phenomenon. Experiments were carried out in an airflow wind tunnel at the University of Guelph, Fluid-Structure Interaction Laboratory.  This study aimed to investigate the geometrical effect of tube array type on the FEI in both transvers and streamwise direction. The stability of a single flexible tube and multiple flexible tubes in tube arrays were tested. The three standard array (parallel triangle, normal triangle and rotated square) were tested for pitch ratio in the range of 1.25 and 1.7. A compression between available experimental data and the current result was presented and conclusions are drawn. The results show that stability threshold was very sensitive to the array pitch-to-diameter ratio and the number of flexible tubes especially in the streamwise direction.

Presenting Author: Amro Elhelaly University of Guelph

Presenting Author Biography: Amro Elhelaly is a PhD. Candidate at university of Guelph.

Authors:

Amro Elhelaly University of Guelph
David Weaver McMaster University
Jovica R. Riznic Canadian Nuclear Safety Commission
Marwan Hassan University of Guelph