Abstract
An intensive research program has been initiated to provide a better understanding of the fundamental aspects of FEI in tube bundles. This paper reports the findings of an experimental investigation utilizing a newly commissioned experimental rig. Initially, a series of water-flow experiments were conducted in a fully flexible, low mass damping parameter, parallel triangular tube array (with a cluster of 9 brass rods). To investigate the effect of pitch ratio on the onset of FEI, four different pitch-to-diameter ratios of 1.27, 1.37, 1.48, and 1.62 were utilized and presented in this study. Moreover, to illustrate the dynamic effect of flat bar support conditions on the stability threshold of FEI, a series of experiments were conducted in each pitch ratio with varied tube/support clearances.
A full description of the flow loop, including the utilized instrumentation, and troubleshooting challenges encountered in commissioning the test rig is discussed. Moreover, the obtained results of the single-phase flow experiments are presented. The current results show good agreement with the available data from previous investigations, which established the confidence level needed to start two-phase experiments.
