Authors: J. E. Moran and D. S. Weaver
9th International Conference on Flow-Induced Vibrations, Czech Republic
Abstract
In heat exchanger tube arrays, fluidelastic instability is a flow-induced vibration mechanism that can produce large oscillations and early tube failure. Thus, it is important to be able to predict the fluidelastic stability threshold of a tube array at the design stage. Unfortunatley, the traditional approach to FEI analysis of tube arrays in two phase flows produces results which do not follow either the general trend observed in single-phase experiments or the predictions of Connors equation. An experimental program was undertaken, introducing a number of changes from the tradional approach in terms of working fluids, void fraction and damping measurement and data analysis. The collapse observed in the resultant stability map suggests that the mechanism of fluidelastic instability is the same in single and two phase flows. In addition, the proposed scaling parameters seem to capture the characteristic features of fluidelastic instability in two phase flows.
