The influence of internal flow on fluidelastic instability of a flexible tube in tube bundles subjected to two-phase cross-flow

This paper investigates the fluidelastic instability of a flexible tube in a rotated triangular tube array subjected to two-phase cross-flow and internal flow. We first established a mathematical model of a flexible tube in the tube bundles conveying flow considering the effect of two-phase cross-flow. Then, the eigenvalue analysis was per-formed to study the influences of the internal flow on the threshold and mechanism of the fluidelastic instability of the tube system in two-phase cross-flow. The results indicate that the internal flow has a significant effect on the threshold of the fluidelastic instability of the tube system in two-phase cross-flow, and may cause different kinds of instabilities. And, the mechanism of the fluidelastic instability of the tube system subjected to two-phase cross-flow and internal flow is notably affected by the tube boundary condition.